


Related Terms 


Coplanar: Set of points, lines, rays, line segments, etc., that lie in the same plane. 
Plane: One of the basic undefined terms of geometry. A plane goes on forever in all directions (in twodimensions) and is "flat" (i.e., it has no thickness).
Line: One of the basic undefined terms of geometry. A line has no thickness but its length goes on forever in two directions.
Point: One of the basic undefined terms of geometry. A point has no length, width, or thickness, and we often use a dot to represent it.
Line Segment: The part of a line between two points on the line. Sometimes referred to as a segment.
Ray: A ray begins at a point and goes on forever in one direction.


