Geometry Basics Vocabulary

Front

A part of a line that extends indefinitely in one direction.

Back

Ray

Front

Adjacent angles that are supplementary.

Back

Linear Pair

Front

A flat surface made up of points that has two dimensions and extends without end.

Back

Plane

Front

A line, ray, or segment that divides an angle or segment into 2 equal parts.

Back

Segment Bisector

Front

2 lines that intersect at a 90 degree angle.

Back

Perpendicular Lines

Front

A straight line that has no endpoints and extends infinitely in both directions.

Back

Line

Front

An angle that measures less than 90 degrees.

Back

Acute Angle

Front

An angle that measures exactly 90 degrees.

Back

Right Angle

Front

An angle that measures more than 90 degrees but less than 180 degrees.

Back

Obtuse Angle

Front

Two angles that are opposite each other when two lines intersect.

Back

Vertical Angles