Geometry Vocabulary

Front

Angle < 90°

Back

Acute angle

Front

Lines that meet or cross at a point.

Back

Intersecting lines.

Front

A set of points forming a straight path extending infinitely in both directions.

Back

Line

Front

Angle > 90° and < 180°

Back

Obtuse angle

Front

Lines that never intersect and are always equidistant.

Back

Parallel lines.

Front

Part of a line that starts at one endpoint and extends infinitely in one direction.

Back

Ray

Front

Angle measuring 90°

Back

Right angle

Front

Part of a line between two endpoints.

Back

Line segment

Front

Lines that intersect at right angles:

Back

Perpendicular lines

Front

Two rays with a common endpoint form an:

Back

angle