Geometry Vocabulary

Front

What is an acute angle?

Back

An angle that measures less than 90 degrees.

Front

What is a right angle?

Back

An angle that measures exactly 90 degrees.

Front

What is an obtuse angle?

Back

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

Front

What is a straight angle?

Back

An angle that measures exactly 180 degrees.

Front

What are parallel lines?

Back

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

Front

What are intersecting lines?

Back

Lines that cross each other at one point.

Front

What are perpendicular lines?

Back

Lines that intersect to form right angles.

Front

What is a circle?

Back

A round shape where all points are the same distance from the center.

Front

What is a diameter?

Back

A line segment that passes through the center of a circle and connects two points on the circle.

Front

What is a radius?

Back

A line segment from the center of a circle to any point on the circle.