Geometry Vocabulary

Front

Points, Lines and Planes are the _________ of Geometry.

Back

Undefined terms

Front

Collinear points are 3 points that lie on the same __________

Back

line

Front

Coplanar points are 3 points that lie on the same __________ but not on the same line.

Back

plane

Front

Lines, line segments and rays are known for their number of endpoints. Lines have __ endpoints, line segments have __ endpoints and rays have __ endpoints.

Back

lines - zero, line segments - 2, rays - 1

Front

Coplanar lines that never intersect are called ______ lines.

Back

Parallel

Front

Non-coplanar lines that never intersect are called ______ lines.

Back

Skew

Front

Coplanar lines intersect at right angles are called ______ lines.

Back

Perpendicular

Front

An angle is defined as two rays that share the same _____.

Back

vertex

Front

Acute angles are angles that are ____

Back

less than 90^o

Front

Obtuse angles are angles that are ____

Back

between 90^o and 180^o