Geometry Terms

Front

Line

Back

Undefined term, made of points, no thickness, extends infinitely in two directions.

Front

Ray

Back

Figure made of points, extends infinitely in one direction from an endpoint.

Front

Segment

Back

Part of a line with two endpoints and points between.

Front

Angle

Back

Figure formed by two rays sharing a common endpoint.

Front

Plane

Back

Undefined term, made of points, no depth, extends infinitely in all directions.

Front

Collinear

Back

Points that lie on the same line.

Front

Coplanar

Back

Points that lie in the same plane.

Front

Congruent

Back

Having the same measure. The symbol used is ≅.

Front

Midpoint

Back

Point halfway between two endpoints.

Front

Bisect

Back

Divide into two congruent pieces.