Lines and Angles Vocabulary

Front

What is a line?

Back

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

Front

What is a line segment?

Back

A line segment is a part of a line that has two endpoints.

Front

What is a ray?

Back

A ray is a part of a line that starts at one endpoint and extends infinitely in one direction.

Front

What is an angle?

Back

An angle is formed by two rays that share a common endpoint, called the vertex.

Front

What is a right angle?

Back

A right angle is an angle that measures exactly 90 degrees.

Front

What is an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.

Front

What is an obtuse angle?

Back

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

Front

What is a straight angle?

Back

A straight angle is an angle that measures exactly 180 degrees.

Front

What are complementary angles?

Back

Complementary angles are two angles whose measures add up to 90 degrees.

Front

What are supplementary angles?

Back

Supplementary angles are two angles whose measures add up to 180 degrees.