Line

A line is the path of one point that is moving. A line is a type of geometric figure. A line has length, but no width. A line is made up of an endless number of points.

 Straight and curved lines 
A line can be straight or curved. In geometry, the word line means a straight line. A straight line is the shortest distance between two points. A straight line is traced by a point moving in a direction that does not change.

A curved line is sometimes called a curve. The edge of a circle is not straight. It is an example of a curve.

 Line segments 
A line segment is part of a line. Here are examples of straight line segments:

 _____   __

 Naming lines 
Lines can get their names from any two points on the line. For example, if a line contains two different points, named  and , then the line can be called either , or .

Sometimes, lines are named with just one symbol. A letter such as  might be used.

 Two lines 
Two lines can be:
 Parallel: Two lines are parallel if they are on the same plane and they never touch.
 Concurrent: Two lines are concurrent if they touch on one point.
 Coincident: Two lines are coincident if they are made of the same points.
 Perpendicular: Two lines are perpendicular if they make four right angles where they touch.
 Skew: In Euclidean space, two lines are skew if they are not parallel but they never touch.

Related pages
 Linear function
 Point (geometry)
 Plane (mathematics)

 References 

Category:Basic English 850 words
Category:Geometry