Classifying Angles and Angle Relationships

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 complementary angles?

Back

Two angles whose measures add up to 90 degrees.

Front

What are supplementary angles?

Back

Two angles whose measures add up to 180 degrees.

Front

What is a linear pair of angles?

Back

A pair of adjacent angles that are formed when two lines intersect.

Front

What are vertical angles?

Back

Angles that are opposite each other when two lines intersect; they are always equal.

Front

If angle A is 30 degrees, what is the measure of its complement?

Back

60 degrees.

Front

If angle B is 120 degrees, what is the measure of its supplement?

Back

60 degrees.