In geometry, a digon is a polygon with two sides (edges) and two vertices. Its construction is degenerate in a Euclidean plane because either the two sides would coincide or one or both would have to be curved; however, it can be easily visualised in elliptic space.
A regular digon has both angles equal and both sides equal and is represented by Schläfli symbol {2}. It may be constructed on a sphere as a pair of 180 degree arcs connecting antipodal points, when it forms a lune.
The digon is the simplest abstract polytope of rank 2.
A truncated "digon", t{2} is a square, {4}. An alternated digon, h{2} is a monogon, {1}.
Great circle
A great circle the largest possible circle that can be drawn on a sphere, one that divides the surface into equal halves, called hemispheres. It is a circle that has the same diameter as the sphere it was drawn on. These curves are geodesics in the sphere and all have the same circumference, that is, the length of the circle.
There are an infinite number of great circles that can be drawn on any perfect sphere. The longitude lines on a globe all form great circles that pass through the same two points (the North Pole and the South Pole). The Equator is another great circle.
Great Circles can be used to determine the shortest surface distance between two points on a sphere (or on the earth).
A straight line from plane Euclidean geometry corresponds to a Great Circle in non-Euclidean spherical geometry.
John Dalton
John Dalton (6 September 1766–27 July 1844) was a British chemist and physicist. He was born in Cumberland to a Quaker family. He is best known for his discoveries in atomic theory. He also made the first important studies of color blindness.
Dalton's Atomic theory is a scientific theory about atoms. Dalton made the theory to explain why the elements would combine in certain ways The idea of atoms was already known at the time, but not widely accepted. Dalton's theory of atoms was based on actual observation. Before this, ideas about atoms were based more on philosophy.
His theory stated that:
Kauniainen
Kauniainen () is a city in Uusimaa, Finland. It is part of the Greater Helsinki area. Kauniainen has an area 6.0 km² and is fully located within Espoo.
Kauniainen has the lowest local taxation rate in Finland (16,5 %). A lot of rich people live there.
Kauniainen was officially founded in 1920. It became a city in 1972. There are about 8,550 people living in Kauniainen. Most of them (57 %) speak Finnish as their first language. 39 % have Swedish as their mother tongue.
Kauniainen has very good bus and train connections. There is a railway station. Many buses drive through Kauniainen.
Nummi-Pusula
Nummi-Pusula is a former municipality in Finland. It was formed in 1981 from the existing municipalities of Nummi and Pusula. The municipality is in Uusimaa and in the province of Southern Finland. On 1 January 2013, it became a part of Lohja.
Nummi-Pusula has an area of . of it is water. About 6,175 people lived there as of 31 December 2012.
Medicine man
A medicine man is a traditional Native American healer. Healing was only part of their function. Another part of their role was as guardian of their belief system, and their rituals.
A very similar role was played in many other mesolithic and neolithic societies, such as pre-modern Africa and New Guinea. This person, man or woman, might help cure physical, mental, or spiritual health problems. A term such as shaman or witch doctor reflects the supernatural element in such roles.
Basement
The basement is the lowest room in some buildings, almost always below the ground. There is another type of basement, called a subcellar. A subcellar is just like a basement, but more below it.
Most basements have lights.
The first famous basements were made sometime in the 1950s. After that, many other kinds of basements were built and made. Later, most basements were used to have washing machines and other items in basements.
Soon, basements were used to contain or save water.
Landfill
A landfill is a place where waste is kept. Waste is usually buried in landfills, but it may first be sorted to remove any recyclable materials.
Landfills have a bad smell and look bad, therefore are usually located far away from where people live.
Once the waste is crushed into very small pieces, it is buried, but without oxygen, a dangerous gas called methane is created. This process is called anaerobic digestion. In some countries, the methane from landfills is used to generate energy.
Roosevelt Regional Landfill, Roosevelt, Washington.
Denver Arapahoe Disposal Site, Aurora, Colorado.
Columbia Ridge Landfill, Arlington, Oregon.
Pine Tree Acres, Lenox, Michigan.
Human reproductive system
A reproductive system is the part of an organism that makes them able to sexually reproduce. Humans and other animals use their reproductive systems to have sexual intercourse as well as reproduce. The reproductive system is one of the human organ systems.
The illustrations here show only human reproductive systems. Other mammals have similar reproductive systems.
Rectum
The rectum is a part of the large intestine which forms a part of the gastrointestinal system. The rectum ends in the anus which is the end of the gastrointestinal system. It is where feces or stools are stored temporarily before coming out of the anus.
Body temperature can also be taken in the rectum. Rectal temperature can be taken by inserting a medical thermometer not more than 25 mm (1 inch) into the rectum via the anus. Normal rectal temperature generally ranges from 36 to 38 °C (97.6 to 100.4 °F) and is about 0.5 °C (1 °F) above oral (mouth) temperature and about 1 °C (2 °F) above axilla (armpit) temperature.
County seat
A county seat is the location of a county government, and is usually the largest, oldest, or most central town or city within a county. In the United Kingdom and Ireland, the name county town is used rather than county seat.
In the U.S. state of Louisiana, counties are called parishes and have parish seats rather than county seats; while in Alaska, counties are called boroughs and have borough seats.
Pacific Islands
Pacific Islands are islands that are in the Pacific Ocean. There are about 20,000 or 30,000 of them. These islands are sometimes called Oceania. The Pacific Islands are in three groups. These groups are Polynesia, Melanesia, and Micronesia. People who live on these islands are called Pacific Islanders. These islands can be made by volcanoes or made on coral reefs. The islands made by volcanoes are bigger, and more people can live on them. The islands made on coral reefs are smaller, and fewer people can live on them. One of Oceania's biggest economic advantages are tourism. As many vacationers come to see the wildlife and the beautiful beaches that span the islands. Major countries and territories include Samoa, Hawaii (U.S), Federal States of Micronesia and French Polynesia.
Island countries in the Pacific Ocean, such as Malaysia, Philippines, East Timor, Japan, Taiwan and most of Indonesia are not considered Pacific Islands since they do not lie in any of the three Oceanic regions. People inhabiting those islands, therefore are not Pacific Islanders.
Large intestine
The large intestine is also called the colon or large bowel. It connects the small intestine to the rectum and anus. It is about 1.5 meters long or 5 feet. It is shorter than the small intestine, but its diameter is larger.
Water is absorbed here and the remaining waste material is stored as faeces before being removed by defecation.
Joensuu
Joensuu is a city in Finland. It is the centre of the region of North Karelia. Joensuu has an area of 2.751,13 km² and a population of 73,076 people. 369.3 km² of the area is water.
The Finnish capital, Helsinki is located 437 km away from Joensuu. There is a university in Joensuu.
The municipalities of Tuupovaara and Kiihtelysvaara were merged with Joensuu on January 1 2005.
Tuupovaara