Geometry Vocabulary

Front

Acute

Back

Less than 90

Front

Obtuse

Back

Greater than 90 and less than 180

Front

An angle whose measure is exactly 90 degrees.

Back

right

Front

An angle that measures greater than 90° but less than 180°

Back

Obtuse angle

Front

Lines that never intersect and are always the same distance apart.

Back

parallel lines

Front

Part of a line that begins at one endpoint and continues without end in one direction.

Back

ray

Front

An angle that measures exactly 90*

Back

right angle

Front

Part of a line between two points on the line (endpoints)

Back

Line segment

Front

Lines that intersect at right angles to form a right angle.

Back

perpendicular lines

Front

Two rays joined at a common endpoint

Back

angle