Circle Circle A circle is easy to make: Draw a curve that is "radius" away from a central point. All points are the same distance from the center. You Can Draw It Yourself Put a pin in a board, put a loop of string around it, and insert a pencil into the loop. Keep the string stretched and draw the circle! Play With It Try dragging the point to see how the radius and cirfcumference change. Radius, Diameter and Circumference The Radius is the distance from the center outwards. The Diameter goes straight across the circle, through the center. The Circumference is the distance once around the circle. And here is the really cool thing: When we divide the circumference by the diameter we get 3.141592654... which is the number π ( Pi ) So when the diameter is 1, the circumference is 3.141592654... We can say: Circumference = π × Diameter Example: You walk around a circle which has a diameter of 100m, how far have you walked?

Distance walked = Circumference = π × 100m = 314m (to the nearest m) Also note that the Diameter is twice the Radius: Diameter = 2 × Radius And so this is also true: Circumference = 2 × π × Radius The length of the words may help you remember: Radius is the shortest word Diameter is longer (and is 2 × Radius) Circumference is the longest (and is π × Diameter) Definition A = 3.14159... × 1.44 = 4.52 (to 2 decimals) Area Compared to a Square A circle has about 80% of the area of a similar-width square. The actual value is (π/4) = 0.785398... = 78.5398...% Names Because people have studied circles for thousands of years special names have come about. Nobody wants to say "that line that starts at one side of the circle, goes through the center and ends on the other side" when a word like "Diameter" will do.

So here are the most common special names: Lines A line that goes from one point to another on the circle's circumference is called a Chord. If that line passes through the center it is called a Diameter. A line that "just touches" the circle as it passes by is called a Tangent. And a part of the circumference is called an Arc. Slices There are two main "slices" of a circle. The "pizza" slice is called a Sector . And the slice made by a chord is called a Segment . Common Sectors The Quadrant and Semicircle are two special types of Sector: Quarter of a circle is called a Quadrant. Half a circle is called a Semicircle. Inside and Outside A circle has an inside and an outside (of course!). But it also has an "on", because we could be right on the circle. Example: "A" is outside the circle, "B" is inside the circle and "C" is on the circle. Geometry and the Circle Unit 2 > Lesson 1 of 6 A circle is an important shape in the field of geometry. Let's look at the definition of a circle and its parts. We will also examine the relationship between the circle and the plane.

A circle is a shape with all points the same distance from its center. A circle is named by its center. Thus, the circle to the right is called circle A since its center is at point A. Some real world examples of a circle are a wheel, a dinner plate and (the surface of) a coin. The distance across a circle through the center is called the diameter. A real-world example of diameter is a 9-inch plate. The radius of a circle is the distance from the center of a circle to any point on the circle. If you place two radii end-to-end in a circle, you would have the same length as one diameter. Thus, the diameter of a circle is twice as long as the radius. We can look at a pizza pie to find real-world examples of diameter and radius. Look at the pizza to the right which has been sliced into 8 equal parts through its center. A radius is formed by making a straight cut from the center to a point on the circle. A straight cut made from a point on the circle, continuing through its center to another point on the circle, is a diameter. As you can see, a circle has many different radii and diameters, each passing through its center.

A chord is a line segment that joins two points on a curve. In geometry, a chord is often used to describe a line segment joining two endpoints that lie on a circle. The circle to the right contains chord AB. If this circle was a pizza pie, you could cut off a piece of pizza along chord AB. By cutting along chord AB, you are cutting off a segment of pizza that includes this chord. A circle has many different chords. Some chords pass through the center and some do not. A chord that passes through the center is called a diameter. It turns out that a diameter of a circle is the longest chord of that circle since it passes through the center. A diameter satisfies the definition of a chord, however, a chord is not necessarily a diameter. This is because every diameter passes through the center of a circle, but some chords do not pass through the center. Thus, it can be stated, every diameter is a chord, but not every chord is a diameter. Let's revisit the definition of a circle. A circle is the set of points that are equidistant from a special point in the plane. The special point is the center. In the circle to the right, the center is point A. Thus we have circle A.

A plane is a flat surface that extends without end in all directions. In the diagram to the right, Plane P contains points A, B and C. Can you think of some real world objects that satisfy the definition of a plane? At this level of mathematics, that is difficult to do. Intuitively, a plane may be visualized as a flat infinite sheet of paper. The top of your desk and a chalkboard are objects which can be used to represent a plane, although they do not satisfy the definition above. A circle divides the plane into three parts: the points INSIDE the circle the points OUTSIDE the circle and the points ON the circle the points inside the circle the points outside the circle the points on the circle You can see an interactive demonstration of this by placing your mouse over the three items below. A circle divides a plane into three parts: the points INSIDE the circle the points OUTSIDE the circle and the points ON the circle Example 1: The length of DB is 2.5 inches Summary: A circle is a shape with all points the same distance from its center. A circle is named by its center. The parts of a circle include a radius, diameter and a chord.

All diameters are chords, but not all chords are diameters. A plane is a flat surface that extends without end in all directions. A circle divides the plane into three parts: The points inside the circle, the points outside the circle and the points on the circle. Exercises Directions: Refer to the diagram to answer each question below. Select your answer by clicking on its button. Feedback to your answer is provided in the RESULTS BOX. If you make a mistake, choose a different button. 1. Which of the following is a chord, but not a diameter? Circles - definition of circles by The Free Dictionary Circles - definition of circles by The Free Dictionary a. A plane curve everywhere equidistant from a given fixed point, the center. b. A planar region bounded by a circle. c. Something, such as a ring, shaped like such a plane curve. 2. A circular or nearly circular course, circuit, or orbit: a satellite's circle around the earth. 3. A traffic circle. 4. A series or process that finishes at its starting point or continuously repeats itself; a cycle. 5. A group of people sharing an interest, activity, or achievement: well-known in artistic circles. 6.

A territorial or administrative division, especially of a province, in some European countries. 7. A sphere of influence or interest; domain. 8. Logic A vicious circle. v. cir·cled, cir·cling, cir·cles v.tr. 1. To make or form a circle around: The hedge circles the fountain. 2. To move in a circle around: The ship circled the island. v.intr. To move in a circle. See Synonyms at turn . Idiom: circle the wagons To take a defensive position; become defensive. [Middle English cercle, from Old French, from Latin circulus, diminutive of circus, circle, from Greek kirkos, krikos; see sker-2 in the Appendix of Indo-European roots.] cir′cler (-klər) n. (ˈsɜːkəl) n 1. (Mathematics) maths a closed plane curve every point of which is equidistant from a given fixed point, the centre.

Equation: (x –h)2 + (y –k)2 = r2 where r is the radius and (h, k) are the coordinates of the centre; area πr2; circumference: 2πr 2. (Mathematics) the figure enclosed by such a curve 3. (Theatre) theatre the section of seats above the main level of the auditorium, usually comprising the dress circle and the upper circle 4. something formed or arranged in the shape of a circle 5. a group of people sharing an interest, activity, upbringing, etc; set: golf circles; a family circle. 6. a domain or area of activity, interest, or influence 7. a circuit 8. a process or chain of events or parts that forms a connected whole; cycle 9. (Physical Geography) a parallel of latitude. See also great circle , small circle 10. the ring of a circus 11. (Archaeology) one of a number of Neolithic or Bronze Age rings of standing stones, such as Stonehenge, found in Europe and thought to be associated with some form of ritual or astronomical measurement 12.

(Hockey (Field & Ice)) hockey See striking circle 13. (Logic) a circular argument. See vicious circle 2 14. come full circle to arrive back at one's starting point. See also vicious circle 15. go round in circles run round in circles to engage in energetic but fruitless activity vb 16. to move in a circle (around): we circled the city by car. 17. (tr) to enclose in a circle; encircle [C14: from Latin circulus a circular figure, from circus ring, circle] ˈcircler n (ˈsɜr kəl) n., v. -cled, -cling. n. 1. a closed plane curve consisting of all points at a given distance from a point within it called the center. 2. the portion of a plane bounded by such a curve. 3. any circular or ringlike object, formation, or arrangement: a circle of dancers. 4. a ring, circlet, or crown. 5. the ring of a circus. 6. a section of seats in a theater. Compare dress circle , family circle (def. 2). 7.

the area within which something acts, exerts influence, etc.; realm; sphere: a wide circle of influence. 8. a series ending where it began or forming a connected whole; cycle. 9. an argument ostensibly proving a conclusion but actually assuming the conclusion as a premise; vicious circle. 10. a number of persons bound by a common tie; coterie: a circle of friends. 11. an administrative division, esp. of a province. 12. a parallel of latitude. 13. a sphere or orb: the circle of the earth. v.t. 14. to enclose in a circle; encircle: Circle the correct answer. 15. to rotate or revolve around: He circled the house cautiously. 16. to bypass; evade: The ship carefully circled the iceberg. v.i. 17. to move in a circle or circuit. Idioms: come full circle, to find oneself back where one started. [1275–1325; Middle English cercle < Old French < Latin circulus=circ(us) (see circus ) + -ulus -ule ] cir′cler, n. The area of a circle is πr2.

The length of the circumference is 2πr. cir·cle (sûr′kəl) A closed curve whose points are all on the same plane and at the same distance from a fixed point (the center). Circle Examples: circle of action, 1752; of admirers, 1793; of acquaintances, 1752; of doctrine, 1531; of fallacy, 1646; of foliages, 1713; of glory, 1595; literary circle; circle of onlookers, 1875; of pleasures, 1759; of passion, 1768; of possibilities, 1644; of probability, 1851; of sciences, 1854; of stars, 1611. circle I will have been circling you will have been circling he/she/it will have been circling we will have been circling you will have been circling they will have been circling Past Perfect Continuous they would have circled circle A balcony or tier in the auditorium.

The dress circle, usually the most expensive seats where spectators used to dress formally, is the first tier. ThesaurusAntonymsRelated WordsSynonymsLegend: Noun 1. circle - ellipse in which the two axes are of equal length; a plane curve generated by one point moving at a constant distance from a fixed point; "he calculated the circumference of the circle" circle of curvature , osculating circle - the circle that touches a curve (on the concave side) and whose radius is the radius of curvature circlet - a small circle equator - a circle dividing a sphere or other surface into two usually equal and symmetrical parts arc - a continuous portion of a circle ellipse , oval - a closed plane curve resulting from the intersection of a circular cone and a plane cutting completely through it; "the sums of the distances from the foci to any point on an ellipse is constant" epicycle - a circle that rolls around (inside or outside) another circle; generates an epicycloid or hypocycloid 2.

circle - an unofficial association of people or groups; "the smart set goes there"; "they were an angry lot" band , lot , set social group - people sharing some social relation car pool - a small group of car drivers who arrange to take turns driving while the others are passengers clique , coterie , ingroup , inner circle , camp , pack - an exclusive circle of people with a common purpose cohort - a band of warriors (originally a unit of a Roman Legion) confederacy , conspiracy - a group of conspirators banded together to achieve some harmful or illegal purpose Four Hundred - the exclusive social set of a city horsey set , horsy set - a set of people sharing a devotion to horses and horseback riding and horse racing jet set - a set of rich and fashionable people who travel widely for pleasure party , company - a band of people associated temporarily in some activity; "they organized a party to search for food"; "the company of cooks walked into the kitchen" 3. circle - something approximating the shape of a circle; "the chairs were arranged in a circle" shape , form - the spatial arrangement of something as distinct from its substance; "geometry is the mathematical science of shape" 4.

locomotion , travel - self-propelled movement pace lap - the first lap of a car race that prepares the cars for a fast start lap of honour , victory lap - a lap by the winning person or team run to celebrate the victory 5. circle - a road junction at which traffic streams circularly around a central island; "the accident blocked all traffic at the rotary" junction - the place where two or more things come together road , route - an open way (generally public) for travel or transportation 6. flunitrazepan , Rohypnol - a depressant and tranquilizer (trade name Rohypnol) often used in the commission of sexual assault; legally available in Europe and Mexico and Colombia 7. circle - a curved section or tier of seats in a hall or theater or opera house; usually the first tier above the orchestra; "they had excellent seats in the dress circle" dress circle seating , seating area , seating room , seats - an area that includes places where several people can sit; "there is seating for 40 students in this classroom" theater , theatre , house - a building where theatrical performances or motion-picture shows can be presented; "the house was full" 8.

rotating mechanism - a mechanism that rotates Verb 1. circle - travel around something; "circle the globe" go , locomote , move , travel - change location; move, travel, or proceed, also metaphorically; "How fast does your new car go?"; "We travelled from Rome to Naples by bus"; "The policemen went from door to door looking for the suspect"; "The soldiers moved towards the city in an attempt to take it before night fell"; "news travelled fast" circumambulate , walk around - walk around something circumnavigate , compass - travel around, either by plane or ship; "We compassed the earth" circle around , circle round , revolve around - move around in a circular motion; "The Earth revolves around the Sun" 2.

circulate go , locomote , move , travel - change location; move, travel, or proceed, also metaphorically; "How fast does your new car go?"; "We travelled from Rome to Naples by bus"; "The policemen went from door to door looking for the suspect"; "The soldiers moved towards the city in an attempt to take it before night fell"; "news travelled fast" orb , orbit , revolve - move in an orbit; "The moon orbits around the Earth"; "The planets are orbiting the sun"; "electrons orbit the nucleus" troll - circulate, move around loop - fly loops, perform a loop; "the stunt pilot looped his plane" loop - move in loops; "The bicycle looped around the tree" 3. shape , form - give shape or form to; "shape the dough"; "form the young child's character" circle noun 1. ring , round , band , disc , loop , hoop , cordon , perimeter , halo The flag was red with a large white circle. The monument consists of a circle of gigantic stones. 3. sphere , world , area , range , field , scene , orbit , realm , milieu She moved only in the most exalted circles.

verb 2. wheel , spiral , revolve , rotate , whirl , pivot There were two helicopters circling around. circle noun حَلَقَةٌ مِنَ الأصْدِقاء دَائِرَة دائِرَهشُرْفَةُ المَسْرَح الدّائِرِيَّهشَكْلٌ دائِري орбита daire daire çizmekdaire içine almak dönmek grup hình tròn John and his circle → Juan y sus amigos , Juan y su peña in certain circles → en ciertos medios to move in fashionable circles → frecuentar los ambientes que están de moda an inner circle of ministers → un grupo de ministros que ostentan mayor poder she moves in wealthy circles → frecuenta la buena sociedad 3. (Brit) (Theat) → anfiteatro m B.

VT the cosmonaut circled the earth → el cosmonauta dio la vuelta a la tierra the aircraft circled the town twice → el avión dio dos vueltas sobre la ciudad to come full circle, to turn full circle → revenir à son point de départ (= group) [people, friends] → cercle m (in cinema, theatre) → balcon m vi [aircraft, bird, pilot] → faire des cercles , décrire des cercles vt (= move round) [+ person, animal] → tourner autour de circle n → Kreis m; to stand in a circle → im Kreis stehen ; to go round in ever decreasing circles (lit) → Spiralen drehen ; (fig) → sich unablässig im Kreis drehen ; to have come or turned full circle (lit) → sich ganz herumgedreht haben, eine Volldrehung gemacht haben; (fig) → wieder da sein , wo man angefangen hat; we’re just going round in circles (fig) → wir bewegen uns nur im Kreise ; to come full circle (fig) → zum Ausgangspunkt zurückkehren ; things have come full circle → der Kreis hat sich geschlossen

 ; when the seasons have come full circle → wenn sich der Kreis der Jahreszeiten schließt (of hills etc) → Ring m, → Kette f; (round the eyes) → Ring m (→ round unter +dat); (in gymnastics) → Welle f; a Celtic stone circle → ein keltischer Steinkreis (Brit Theat) → Rang m ?

dress circle , upper circle (= group of persons) → Kreis m, → Zirkel m (geh); a close circle of friends → ein enger Freundeskreis ; in political circles → in politischen Kreisen ; the family circle → der engste Familienkreis ; the whole family circle → die ganze Familie ; he’s moving in different circles now → er verkehrt jetzt in anderen Kreisen vt (= surround) → umgeben (= move around) → kreisen um; the enemy circled the town → der Feind kreiste die Stadt ein (= draw a circle round) → einen Kreis or Kringel machen um; he circled several of the addresses → er machte einen Kreis um mehrere der Anschriften ; circled in red → rot umkringelt vi (= fly in a circle) → kreisen circle great/small circle (Geom) → cerchio massimo /minore to stand in a circle → mettersi in cerchio she moves in wealthy circles → frequenta l'alta società 3. vi → girare in circolo circle (ˈsəːkl) noun 1.

a figure (O) bounded by one line, every point on which is equally distant from the centre. sirkel دائِرَه окръжност círculo kruh, kružnice der Kreis cirkel κύκλος círculo ringjoon دایره ympyrä cercle עגול , עיגול वृत्त, परिधि krug kör lingkaran hringur cerchio 円 원 apskritimas, skritulys aplis; riņķis bulatan cirkel sirkel , ring koło دایره círculo cerc круг kruh, kružnica krog krug cirkel วงกลม çember , daire , halka 圓 круг دائرہ hình tròn 圆 2. something in the form of a circle. She was surrounded by a circle of admirers.

kring شَكْلٌ دائِري кръг círculo kruh der Kreis kreds κύκλος círculo ring حلقه rengas cercle מעגל मण्डली krug, kružnica, kolut kör lingkungan hópur circolo 円形のもの 원형 ratas loks keliling kring krets , sirkel , ring krąg حلقه círculo cerc круг ; кольцо kruh krog krug krets, ring ทรงกลม halka 環繞物 коло گھیرا ، حلقہ vòng tròn 环状物 3. a group of people. a circle of close friends; wealthy circles.

kring حَلَقَةٌ مِنَ الأصْدِقاء група хора círculo kroužek, skupina der Kreis kreds κύκλος círculo ring جرگه؛ دسته piiri cercle , milieu חוג मण्डली krug (társasági stb.) kör kelompok klíka, hópur cerchia 仲間 사람들 그룹 būrelis aprindas; pulciņš kumpulan kring krets krąg جرګه círculo cerc, mediu круг krúžok krog, sloj krug krets กลุ่มคน çevre , grup (興趣相同的人形成的)圈子 коло لوگوں کا گروہ nhóm người （兴趣相同的人形成的）圈子 4. a balcony in a theatre etc. We sat in the circle at the opera. balkon شُرْفَةُ المَسْرَح الدّائِرِيَّه театр.

балкон balcão balkon (v hledišti) der Rang balkon εξώστης anfiteatro rõdu ردیف صندلی های بالکن parvi balcon יציע सिनेमा हाल इत्यादि में बाल्कनी balkon erkély (színházban) balkon svalir galleria さじき席 (극장의) 원형 관람석 balkonas balkons beranda bulat balcon galleri , balkong balkon د برنډى چوكى balcão balcon ярус balkón balkon v gledališču balkon galleri ระเบียงในโรงมหรสพ balkon (劇場的)樓廳 ярус تھئیٹر کی بالکونی ban công （剧场的）楼厅 verb 1. to move in a circle round something. The chickens circled round the farmer who was bringing their food.

omring يَدور обикалям cercar kroužit (kolem), obklopovat umkreisen kredse σχηματίζω κύκλο γύρω από rodear tiirlema دور چیزی گشتن kiertää tourner autour de לְהַקִיף समूह में चक्कर मारना kružiti körbejár mengelilingi mynda hring girare in circolo 回る (~의) 주위를 돌다 suktis riņķot; aptvert membuat bulatan rondcirkelen kretse , gå i ring otoczyć kołem په یوه شی دور کی ګرځیدل cercar a se învârti în jurul (...) окружать krúžiť; obiehať krožiti kružiti gå (springa, cirkla, kretsa) runt เคลื่อนเป็นวงกลม dönmek , daire çizmek 環繞 оточуват

и دائرے میں گھمانا bao quanh 环绕 2.

to draw a circle round. Please circle the word you think is wrong.

omkring يَرْسُمُ دائِرَةً заграждам desenhar um círculo zakroužkovat umkreisen tegne en cirkel; lave en cirkel βάζω σε κύκλο trazar un círculo ringi ümber tõmbama دور چیزی خط کشیدن ympäröidä encercler לְהַקִיף घेरना okružiti bekarikáz melingkari teikna/gera hring cerchiare 丸をつける 원을 그리다 apibrėžti (rateliu) apvilkt apli melukis bulatan omcirkelen tegne en sirkel rundt zakreślać د يو شى تر شاو خوا كرښه ايستنه desenhar um círculo a încercui обводить кружком zakrúžkovať obkrožiti zaokružiti göra (rita) en ring (cirkel) runt วาดเป็นวง

กลม daire içine almak 畫圈 взяти в коло کسی چیز کے گرد دائرہ کھینچنا khoanh tròn 画圈 circle Quandaries & Queries at Math Central 2006-09-22 From Kim: An equilateral triangle has been wedged in between two circles.

How does the diameter of the smaller circle compare to the diameter of the larger circle. image: circle inside of an equilateral triangle touching all sides of the triangle; both the triangle and the circle inside are placed into a larger circle where the triangle vertices all touch the circle Answered by Penny Nom. Three circles inside a larger circle 2006-04-16 From Meghan: Given three congruent circles tangent to one another (radii = 1), what is the radius of a circle circumscribed around them? Answered by Stephen La Rocque. Overlapping area of two circles 2006-04-15 From Jade: Given two identical circles where the radius (6 units) is the distance between the centers, what is the area of the overlapping region? Answered by Stephen La Rocque. An epicycloid 2006-04-10 From Sharon: What is the name of the curve formed by a point on the circumference of a circle that rolls on the outside of a fixed circle? This curve is used in the study of gears. Answered by Stephen La Rocque and Penny Nom.

Two circles 2006-04-07 From Louisa: One circle of radius 7cm is touching another circle of radius 4cm. These circles are on a line and the problem is to find the length AB where A is the point marking the bottom of the radius of one circle and B is the point marking the bottom of the radius of the other circle. Answered by Stephen La Rocque. From Sarah: Moving as many circles as you need, make 2 rows of 4 circles only having 6 circles? Answered by Chris Fisher. How is the area of an arc (alpha*pi*r squared/360) derived? How is the length of an arc (alpha*pi*r/180) derived? Answered by Penny Nom. A sequence of circles and tangents 2006-01-16 From Paul: Consider a circle whose center is (2,2) and whose radius is 1, and the straight line that goes through the origin and that is tangent to this circle so that the intersection between them is as shown in the attached picture.

With this new point we make a new circle whose radius is half of the first one, and we calculate the corresponding intersection point with the same suppositions as in the first case. We repeat the process to the infinite. Find the distance between the center of the circle in the infinite and the origin (point (0,0)). Answered by Chris Fisher. From Ananth: I have one bigger circle A with radius 15. Inside this bigger circle i have another circle B with radius 3 which touch this bigger circle. Have another circle C with radius 4 which touches A and B. I would like to draw a biggest circle which touches A,B and C. Answered by Chris Fisher. Framing an arched wall 2005-08-12 From Mike: I'm framing a building wall with a curved (arcing) top section. The radius of the section is 74'6" with a height above finish floor of 16'0". The horizontal run of the arced section is 23' 1 1/2" with a low height above finish floor of 12'4".

If I start with a 16' stud at the high end how long are the subsequent studs if they are on 16" centers? Short of laying this out on a tennis court how can I work out the lengths of the studs? Answered by Penny Nom. Two overlapping circles 2005-03-20 From Safi: I have a problem to calculate the area of two overlapping circles because two circles are overlap then how i calculate the overlap area to subtract from the area of both circle. Answered by Penny Nom. Three tangent circles 2005-01-25 From Kate: Two circles, C1 and C2, touch each other externally; and the line l is a common tangent. The line m is parallel to l and touches the two circls C1 and C3. The three circles are mutually tangent. If the radius of C2 is 9 and if the radius of C3 is 4, what is the radius of C1? Answered by Chris Fisher.

Arcs and chords 2005-01-09 From Aniesha: A chord of a circle is 48 centimeters long and is 10 centimeters from the center of the circle. Find the radius? Answered by Penny Nom. Irrigation and a sector of a circle 2004-12-23 From Chuck: A friend of mine is a farmer and uses Pivots to irrigate portions of his land. The crop rows are in straight lines that all form chords of a large circle. The intent is to determine area between any two "boundary" rows expressed in acres. Answered by Harley Weston. A regular hexagon is inscribed in a circle. 2004-12-08 From Abraham: A regular hexagon is inscribed in a circle. What is the ratio of the length of a side of the hexagon to the minor arc that it intercepts?

(1) pi/6 (3) 3/pi (This is the correct answer.) (4) 6/pi I found the length of the minor arc to be (pi)(r)/3 by doing a sixth of the circumference(2pi r).But I can't find the length of the radius to finish off the problem. If I knew the radius I would then plug it into the above and then use the radius again to be the length of the side because the triangle(one of the six of a hexagon) is equilateral. But can you show me how to get the radius to be 3? Thank you so much. Answered by Walter Whiteley. A belt around two pulleys 2004-12-07 From Ian: a belt is stretched around two pulleys whose centers are d units apart and whose radii are R and r respectively (obviously R+r<d). the challenge is to find the length of the belt, l as a formula in terms of R, r, and d only. Answered by Penny Nom.

An arc of a circle 2004-12-05 From Ruben: i have an arc 55 inches wide, 12 inches high at the centerline of the arc. how can i determine the diameter of the circle that would correspond to the arc. Answered by Penny Nom. Circles in a hexagon 2004-04-11 From Crystal: step by step can you show me how to calculate the area of the region inside the hexagon but outside the seven circles. given the radius of each circle is one inch Answered by Penny Nom. A theorem in geometry 2003-09-02 From Diego: Please refer to figure in attached file. P is a point on the chord AB of a circle such that the tangent PT which touches the circle at T is equal to AB. How do we prove that PT2 = AP x BP. Answered by Dieter Ruoff and Penny Nom. Definitions and descriptions 2003-06-08 From Tammy: MY DAUGHTERS TEACHER ASKED HER TO GIVE BOTH A DESCRIPTION AND A DEFINITION OF THE FOLLOWING ... CIRCLE, SQUARE, TRIANGLE,HEXAGON......

THE LIST GOES ON. WHAT IS THE DIFFERENCE BETWEEN DEFINITION AND DESCRIPTION ? DO A CIRCLE FOR AN EXAMPLE PLEASE. Answered by Penny Nom. A circle, tangent to two circles and a line 2003-04-30 From Keith: I have a horizontal line (that is treated as a datum line or the X axis), with two circles having their center points at different heights from that line (X1,Y1 & X2,Y2). The two circles are also at different diameters (R1 & R2). Both circles and the line (X-Axis) do not intersect nor are they tangent. My goal is to determine the maximum diameter of an inscribed circle that will fit between all three. Answered by Chris Fisher and Harley Weston. I have three circles...

2003-01-30 From Tony: I HAVE THREE CIRCLE THAT IS CIRCLE TOGETHER: IN CIRCLE A, THE NUMBERS ARE: 11 I KNOW IS IN CIRCLE A, BUT I HAVE THE: 5 THAT IN A AND C, I HAVE THE 2 IN THE CIRCLE C AND B AND AND A, THE CIRCLE C I KNOW THAT 10 IS IN THE CIRCLE THE 4 IN CIRCLE A: AND B: IN CIRCLE B, I KNOW NUMBER 13 IS IN CIRCLE B; BUT I HAVE THE 3 IN CIRCLE B AND C AND I HAVE THE 2 IN CIRCLE B AND C AND A ,THE 4 IN CIRCLE B AND A. HOW DO I FIND THE SUM IN CIRCLE C AND IN B IN BOTH CIRCLE A AND B AND B AND C NOT IN CIRCLE B, AND NOT CIRCLE C. Answered by Penny Nom. Constructing a tangent to two circles 2002-11-28 From Tom: I have two circles, different sizes a known distance from each other. We know the radii of the circles.

How do I construct a line that is tangent to both circles relative to the segment that connects the centers of both circles? Answered by Chris Fisher and Penny Nom. Say you have a cirlcle. Then you draw 2 dots on the circle. Then you connect the dots with lines. The circle is divided into 2 parts. If you do the same with 3 dots and connect each dot to each dot with a line then you get a circle with 4 parts. 4 dots with lines connecting all (6 lines) = 8 parts.... Answered by Claude Tardif. A Circle is evenly divided into six equal triangles 2002-09-16 From Marilynn: A Circle is evenly divided into six equal triangles leaving an area between the outside of the circle and the one side of the triangle. This area is measured as 3.14. What is the length of the radius, one line on the triangle? Answered by Paul Betts. What is the circumference of a 72" diameter circle? Answered by Penny Nom.

Overlapping circles 2002-05-29 From Naman: There are two circles, big circle with radius R and small one with radius r. They intersect and overlap in such a way that the common area formed is 1/2 pi r 2 (half the area of the small circle) If r=1, find the Radius of the big circle (R)? Answered by Harley Weston. Chord length 2002-05-17 From Ashlie: How do you find the chord length of one section of a chord if you only have the diameter length and the other whole chord length. WV is the diameter and equals 16. XY is perpendicular to it, and equals 10. They intersect at pt. Z. I need to know what WZ equals. Please help! Answered by Penny Nom. Three chords 2001-06-28 From Paul: AE is a diameter of a circle and AC, CD and DE are chords of lengths 1, 2 and 3 respectively. (See the diagram.) Find the ridius of the circle. Answered by Harley Weston.

Three tangents to a circle 2001-06-27 From Stephanie: The three lines PS, PT, and RQ are tangents to the circle. The points S, X, and T are the three points of tangency. Prove that the perimeter of triangle PQR is equal to 2PT. Answered by Chris Fisher. How is an ellipse like a circle? In what way does an ellipse have a center? How is a hyperbola similar and different to an ellipse? How is a parabola similar a different to a circle ellipse and parabola? Answered by Pnny Nom. A quarter-circle and two semi-circles 2000-12-31 From Christopher: Inside the quarter-circle are two semi-circles with the same radius, (r). Which has a greater area, G or L? Answered by Penny Nom. Grazing area for a goat 2000-03-10 From Amy: A goat is tied in the middle of a side of a square building whose sides are 2 yards long. The rope is 4 yards long. What is the grazing area for the goat? Answered by Harley Weston.

Rolling Circles 1999-09-12 From Craig Ellis: We have a circle of radius 3. inside the circle and tangent to the circle of radius 3 at one point is a circleof radius 1. The question is if we could roll the smaller circle around the inside of the larger circle how many revolutions would it take to get around to where we started. Answered by Chris Fisher and Walter Whiteley. Circles, cirmcuference and area 1999-05-16 From Stephen Ehrler: I would appreciate if you could please tell me if what I discovered here is something or my ignorance? I noticed that a circle with r radii has the folling characteristic. r = [2 * ( pi * r2 / pi * 2r)] The equation states that the ratio of a circles area over its circumfrence = 1/2 that of the circles radii. It works every time. Did you know this ? Is it some kind of therom and can it be used for any thing? I thought this was intresting and would appreciate any input you may have. Thank you.

Circles 1999-04-21 From Alex Elkins: How do you find the circumference of a circle if you only know the radius and the square feet or inches of the circle if the radius is 18 inches, If done in inches do you multiply by 12 to get the square feet? Answered by Jack Lesage and Harley Weston. Two Inscribed Trapezoids 1998-01-27 From James: A hexagon inscribed in a circle has three consecutive sides each of length 3 and three consecutive sides each of length 5. The chord of the circle that divides the hexagon into two trapezoids, one with three sides each of length 3 and the other with three sides each of length 5, has length equal to m/n, where m and n are relatively prime positive integers. Find m+n. Answered by Haragauri Gupta. A geometry problem 1997-11-20 From Herman: When produced, two equal chords AB and CD of a circle meet at P in an angle of 24 degrees.

If H is the mid-point of AB and K is the mid-point of CD, calculate the size of angle HKD. Answered by Penny Nom. The Length of a Chord. 1997-07-26 From Nathan Arthur: Picture a 9 inch diameter circle. Inside that circle is a 6 inch diameter circle tangent to it. Then, tangent to both circles is a 3 inch diameter circle. So there are three circles, two smaller ones inside a big one, all of them just touching but not overlapping. Now picture a chord on the 9 inch circle that is created by making a line that is tangent to both the 6 and the 3 inch circles and extending it to the edge of the 9 inch circle. I need the length of that cord. Answered by Chris Fisher. Area Between Two Sectors 1997-03-02 From Rebecca Henry: Points A,B,C,D,E,F are equally spaced on a unit circle. Arc CGE has a center A. Find the number of square units of area in the shaded region. Answered by Walter Whiteley. Some Circle Questions.

1997-02-25 From Staci Vawser: A circle with a radius of 10m is drawn. A chord is drawn across the circle. How is the area that is formed between the chord and the arc calculated? Answered by Harley Weston. Circle (geometry) - definition of Circle (geometry) by The Free Dictionary Circle (geometry) - definition of Circle (geometry) by The Free Dictionary a. A plane curve everywhere equidistant from a given fixed point, the center. b. A planar region bounded by a circle. c. Something, such as a ring, shaped like such a plane curve. 2. A circular or nearly circular course, circuit, or orbit: a satellite's circle around the earth. 3. A traffic circle. 4. A series or process that finishes at its starting point or continuously repeats itself; a cycle. 5. A group of people sharing an interest, activity, or achievement: well-known in artistic circles. 6. A territorial or administrative division, especially of a province, in some European countries. 7. A sphere of influence or interest; domain. 8. Logic A vicious circle. v. cir·cled, cir·cling, cir·cles v.tr.

1. To make or form a circle around: The hedge circles the fountain. 2. To move in a circle around: The ship circled the island. v.intr. To move in a circle. See Synonyms at turn . Idiom: circle the wagons To take a defensive position; become defensive. [Middle English cercle, from Old French, from Latin circulus, diminutive of circus, circle, from Greek kirkos, krikos; see sker-2 in the Appendix of Indo-European roots.] cir′cler (-klər) n. (ˈsɜːkəl) n 1. (Mathematics) maths a closed plane curve every point of which is equidistant from a given fixed point, the centre. Equation: (x –h)2 + (y –k)2 = r2 where r is the radius and (h, k) are the coordinates of the centre; area πr2; circumference: 2πr 2. (Mathematics) the figure enclosed by such a curve 3. (Theatre) theatre the section of seats above the main level of the auditorium, usually comprising the dress circle and the upper circle 4.

something formed or arranged in the shape of a circle 5. a group of people sharing an interest, activity, upbringing, etc; set: golf circles; a family circle. 6. a domain or area of activity, interest, or influence 7. a circuit 8. a process or chain of events or parts that forms a connected whole; cycle 9. (Physical Geography) a parallel of latitude. See also great circle , small circle 10. the ring of a circus 11. (Archaeology) one of a number of Neolithic or Bronze Age rings of standing stones, such as Stonehenge, found in Europe and thought to be associated with some form of ritual or astronomical measurement 12. (Hockey (Field & Ice)) hockey See striking circle 13. (Logic) a circular argument. See vicious circle 2 14. come full circle to arrive back at one's starting point. See also vicious circle 15. go round in circles run round in circles to engage in energetic but fruitless activity vb 16. to move in a circle (around): we circled the city by car. 17.

(tr) to enclose in a circle; encircle [C14: from Latin circulus a circular figure, from circus ring, circle] ˈcircler n (ˈsɜr kəl) n., v. -cled, -cling. n. 1. a closed plane curve consisting of all points at a given distance from a point within it called the center. 2. the portion of a plane bounded by such a curve. 3. any circular or ringlike object, formation, or arrangement: a circle of dancers. 4. a ring, circlet, or crown. 5. the ring of a circus. 6. a section of seats in a theater. Compare dress circle , family circle (def. 2). 7. the area within which something acts, exerts influence, etc.; realm; sphere: a wide circle of influence. 8. a series ending where it began or forming a connected whole; cycle. 9. an argument ostensibly proving a conclusion but actually assuming the conclusion as a premise; vicious circle. 10. a number of persons bound by a common tie; coterie: a circle of friends. 11. an administrative division, esp. of a province. 12. a parallel of latitude.

13. a sphere or orb: the circle of the earth. v.t. 14. to enclose in a circle; encircle: Circle the correct answer. 15. to rotate or revolve around: He circled the house cautiously. 16. to bypass; evade: The ship carefully circled the iceberg. v.i. 17. to move in a circle or circuit. Idioms: come full circle, to find oneself back where one started. [1275–1325; Middle English cercle < Old French < Latin circulus=circ(us) (see circus ) + -ulus -ule ] cir′cler, n. The area of a circle is πr2. The length of the circumference is 2πr. cir·cle (sûr′kəl) A closed curve whose points are all on the same plane and at the same distance from a fixed point (the center).

Circle Examples: circle of action, 1752; of admirers, 1793; of acquaintances, 1752; of doctrine, 1531; of fallacy, 1646; of foliages, 1713; of glory, 1595; literary circle; circle of onlookers, 1875; of pleasures, 1759; of passion, 1768; of possibilities, 1644; of probability, 1851; of sciences, 1854; of stars, 1611. circle I will have been circling you will have been circling he/she/it will have been circling we will have been circling you will have been circling they will have been circling Past Perfect Continuous they would have circled circle A balcony or tier in the auditorium. The dress circle, usually the most expensive seats where spectators used to dress formally, is the first tier. ThesaurusAntonymsRelated WordsSynonymsLegend: Noun 1.

circle - ellipse in which the two axes are of equal length; a plane curve generated by one point moving at a constant distance from a fixed point; "he calculated the circumference of the circle" circle of curvature , osculating circle - the circle that touches a curve (on the concave side) and whose radius is the radius of curvature circlet - a small circle equator - a circle dividing a sphere or other surface into two usually equal and symmetrical parts arc - a continuous portion of a circle ellipse , oval - a closed plane curve resulting from the intersection of a circular cone and a plane cutting completely through it; "the sums of the distances from the foci to any point on an ellipse is constant" epicycle - a circle that rolls around (inside or outside) another circle; generates an epicycloid or hypocycloid 2.

circle - an unofficial association of people or groups; "the smart set goes there"; "they were an angry lot" band , lot , set social group - people sharing some social relation car pool - a small group of car drivers who arrange to take turns driving while the others are passengers clique , coterie , ingroup , inner circle , camp , pack - an exclusive circle of people with a common purpose cohort - a band of warriors (originally a unit of a Roman Legion) confederacy , conspiracy - a group of conspirators banded together to achieve some harmful or illegal purpose Four Hundred - the exclusive social set of a city horsey set , horsy set - a set of people sharing a devotion to horses and horseback riding and horse racing jet set - a set of rich and fashionable people who travel widely for pleasure party , company - a band of people associated temporarily in some activity; "they organized a party to search for food"; "the company of cooks walked into the kitchen" 3. circle - something approximating the shape of a circle; "the chairs were arranged in a circle" shape , form - the spatial arrangement of something as distinct from its substance; "geometry is the mathematical science of shape" 4.

locomotion , travel - self-propelled movement pace lap - the first lap of a car race that prepares the cars for a fast start lap of honour , victory lap - a lap by the winning person or team run to celebrate the victory 5. circle - a road junction at which traffic streams circularly around a central island; "the accident blocked all traffic at the rotary" junction - the place where two or more things come together road , route - an open way (generally public) for travel or transportation 6. flunitrazepan , Rohypnol - a depressant and tranquilizer (trade name Rohypnol) often used in the commission of sexual assault; legally available in Europe and Mexico and Colombia 7. circle - a curved section or tier of seats in a hall or theater or opera house; usually the first tier above the orchestra; "they had excellent seats in the dress circle" dress circle seating , seating area , seating room , seats - an area that includes places where several people can sit; "there is seating for 40 students in this classroom" theater , theatre , house - a building where theatrical performances or motion-picture shows can be presented; "the house was full" 8.

rotating mechanism - a mechanism that rotates Verb 1. circle - travel around something; "circle the globe" go , locomote , move , travel - change location; move, travel, or proceed, also metaphorically; "How fast does your new car go?"; "We travelled from Rome to Naples by bus"; "The policemen went from door to door looking for the suspect"; "The soldiers moved towards the city in an attempt to take it before night fell"; "news travelled fast" circumambulate , walk around - walk around something circumnavigate , compass - travel around, either by plane or ship; "We compassed the earth" circle around , circle round , revolve around - move around in a circular motion; "The Earth revolves around the Sun" 2.

circulate go , locomote , move , travel - change location; move, travel, or proceed, also metaphorically; "How fast does your new car go?"; "We travelled from Rome to Naples by bus"; "The policemen went from door to door looking for the suspect"; "The soldiers moved towards the city in an attempt to take it before night fell"; "news travelled fast" orb , orbit , revolve - move in an orbit; "The moon orbits around the Earth"; "The planets are orbiting the sun"; "electrons orbit the nucleus" troll - circulate, move around loop - fly loops, perform a loop; "the stunt pilot looped his plane" loop - move in loops; "The bicycle looped around the tree" 3. shape , form - give shape or form to; "shape the dough"; "form the young child's character" circle noun 1. ring , round , band , disc , loop , hoop , cordon , perimeter , halo The flag was red with a large white circle. The monument consists of a circle of gigantic stones. 3. sphere , world , area , range , field , scene , orbit , realm , milieu She moved only in the most exalted circles.

verb 2. wheel , spiral , revolve , rotate , whirl , pivot There were two helicopters circling around. circle noun حَلَقَةٌ مِنَ الأصْدِقاء دَائِرَة دائِرَهشُرْفَةُ المَسْرَح الدّائِرِيَّهشَكْلٌ دائِري орбита daire daire çizmekdaire içine almak dönmek grup hình tròn John and his circle → Juan y sus amigos , Juan y su peña in certain circles → en ciertos medios to move in fashionable circles → frecuentar los ambientes que están de moda an inner circle of ministers → un grupo de ministros que ostentan mayor poder she moves in wealthy circles → frecuenta la buena sociedad 3. (Brit) (Theat) → anfiteatro m B.

VT the cosmonaut circled the earth → el cosmonauta dio la vuelta a la tierra the aircraft circled the town twice → el avión dio dos vueltas sobre la ciudad to come full circle, to turn full circle → revenir à son point de départ (= group) [people, friends] → cercle m (in cinema, theatre) → balcon m vi [aircraft, bird, pilot] → faire des cercles , décrire des cercles vt (= move round) [+ person, animal] → tourner autour de circle n → Kreis m; to stand in a circle → im Kreis stehen ; to go round in ever decreasing circles (lit) → Spiralen drehen ; (fig) → sich unablässig im Kreis drehen ; to have come or turned full circle (lit) → sich ganz herumgedreht haben, eine Volldrehung gemacht haben; (fig) → wieder da sein , wo man angefangen hat; we’re just going round in circles (fig) → wir bewegen uns nur im Kreise ; to come full circle (fig) → zum Ausgangspunkt zurückkehren ; things have come full circle → der Kreis hat sich geschlossen

 ; when the seasons have come full circle → wenn sich der Kreis der Jahreszeiten schließt (of hills etc) → Ring m, → Kette f; (round the eyes) → Ring m (→ round unter +dat); (in gymnastics) → Welle f; a Celtic stone circle → ein keltischer Steinkreis (Brit Theat) → Rang m ?

dress circle , upper circle (= group of persons) → Kreis m, → Zirkel m (geh); a close circle of friends → ein enger Freundeskreis ; in political circles → in politischen Kreisen ; the family circle → der engste Familienkreis ; the whole family circle → die ganze Familie ; he’s moving in different circles now → er verkehrt jetzt in anderen Kreisen vt (= surround) → umgeben (= move around) → kreisen um; the enemy circled the town → der Feind kreiste die Stadt ein (= draw a circle round) → einen Kreis or Kringel machen um; he circled several of the addresses → er machte einen Kreis um mehrere der Anschriften ; circled in red → rot umkringelt vi (= fly in a circle) → kreisen circle great/small circle (Geom) → cerchio massimo /minore to stand in a circle → mettersi in cerchio she moves in wealthy circles → frequenta l'alta società 3. vi → girare in circolo circle (ˈsəːkl) noun 1.

a figure (O) bounded by one line, every point on which is equally distant from the centre. sirkel دائِرَه окръжност círculo kruh, kružnice der Kreis cirkel κύκλος círculo ringjoon دایره ympyrä cercle עגול , עיגול वृत्त, परिधि krug kör lingkaran hringur cerchio 円 원 apskritimas, skritulys aplis; riņķis bulatan cirkel sirkel , ring koło دایره círculo cerc круг kruh, kružnica krog krug cirkel วงกลม çember , daire , halka 圓 круг دائرہ hình tròn 圆 2. something in the form of a circle. She was surrounded by a circle of admirers.

kring شَكْلٌ دائِري кръг círculo kruh der Kreis kreds κύκλος círculo ring حلقه rengas cercle מעגל मण्डली krug, kružnica, kolut kör lingkungan hópur circolo 円形のもの 원형 ratas loks keliling kring krets , sirkel , ring krąg حلقه círculo cerc круг ; кольцо kruh krog krug krets, ring ทรงกลม halka 環繞物 коло گھیرا ، حلقہ vòng tròn 环状物 3. a group of people. a circle of close friends; wealthy circles.

kring حَلَقَةٌ مِنَ الأصْدِقاء група хора círculo kroužek, skupina der Kreis kreds κύκλος círculo ring جرگه؛ دسته piiri cercle , milieu חוג मण्डली krug (társasági stb.) kör kelompok klíka, hópur cerchia 仲間 사람들 그룹 būrelis aprindas; pulciņš kumpulan kring krets krąg جرګه círculo cerc, mediu круг krúžok krog, sloj krug krets กลุ่มคน çevre , grup (興趣相同的人形成的)圈子 коло لوگوں کا گروہ nhóm người （兴趣相同的人形成的）圈子 4. a balcony in a theatre etc. We sat in the circle at the opera. balkon شُرْفَةُ المَسْرَح الدّائِرِيَّه театр.

балкон balcão balkon (v hledišti) der Rang balkon εξώστης anfiteatro rõdu ردیف صندلی های بالکن parvi balcon יציע सिनेमा हाल इत्यादि में बाल्कनी balkon erkély (színházban) balkon svalir galleria さじき席 (극장의) 원형 관람석 balkonas balkons beranda bulat balcon galleri , balkong balkon د برنډى چوكى balcão balcon ярус balkón balkon v gledališču balkon galleri ระเบียงในโรงมหรสพ balkon (劇場的)樓廳 ярус تھئیٹر کی بالکونی ban công （剧场的）楼厅 verb 1. to move in a circle round something. The chickens circled round the farmer who was bringing their food.

omring يَدور обикалям cercar kroužit (kolem), obklopovat umkreisen kredse σχηματίζω κύκλο γύρω από rodear tiirlema دور چیزی گشتن kiertää tourner autour de לְהַקִיף समूह में चक्कर मारना kružiti körbejár mengelilingi mynda hring girare in circolo 回る (~의) 주위를 돌다 suktis riņķot; aptvert membuat bulatan rondcirkelen kretse , gå i ring otoczyć kołem په یوه شی دور کی ګرځیدل cercar a se învârti în jurul (...) окружать krúžiť; obiehať krožiti kružiti gå (springa, cirkla, kretsa) runt เคลื่อนเป็นวงกลม dönmek , daire çizmek 環繞 оточуват

и دائرے میں گھمانا bao quanh 环绕 2.

to draw a circle round. Please circle the word you think is wrong.

omkring يَرْسُمُ دائِرَةً заграждам desenhar um círculo zakroužkovat umkreisen tegne en cirkel; lave en cirkel βάζω σε κύκλο trazar un círculo ringi ümber tõmbama دور چیزی خط کشیدن ympäröidä encercler לְהַקִיף घेरना okružiti bekarikáz melingkari teikna/gera hring cerchiare 丸をつける 원을 그리다 apibrėžti (rateliu) apvilkt apli melukis bulatan omcirkelen tegne en sirkel rundt zakreślać د يو شى تر شاو خوا كرښه ايستنه desenhar um círculo a încercui обводить кружком zakrúžkovať obkrožiti zaokružiti göra (rita) en ring (cirkel) runt วาดเป็นวง

กลม daire içine almak 畫圈 взяти в коло کسی چیز کے گرد دائرہ کھینچنا khoanh tròn 画圈 circle

Question: What name, geometrically, is given to a circle which rolls around inside or outside another circle?
Answer: EPICYCLE