2D Shapes - Vocabulary

Front

What is a plane?

Back

A flat surface that goes on forever in all directions.

Front

What is a line segment?

Back

Part of a line between two endpoints.

Front

What is the measure of a right angle?

Back

90 degrees.

Front

What is the measure of an acute angle?

Back

Less than 90 degrees.

Front

What are perpendicular lines?

Back

Intersecting lines that meet to form four right angles.

Front

What is a ray?

Back

A line that has an endpoint and goes on forever in one direction.

Front

What is a point in geometry?

Back

An exact location in space represented by a dot.

Front

What is a line in geometry?

Back

A straight path that goes on forever in both directions.

Front

What is the difference between a line and a line segment?

Back

A line goes on forever, while a line segment has two endpoints.

Front

What is an obtuse angle?

Back

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