Angle vocabulary

Front

What are supplementary angles?

Back

Two angles that add up to 180 degrees.

Front

What is a straight angle?

Back

An angle that measures exactly 180 degrees.

Front

What are vertical angles?

Back

Angles that are opposite each other when two lines intersect; they are always congruent (equal measures).

Front

What is an obtuse angle?

Back

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

Front

What is an acute angle?

Back

An angle that measures less than 90 degrees.

Front

What are complementary angles?

Back

Two angles that add up to 90 degrees.

Front

What is a right angle?

Back

An angle that measures exactly 90 degrees.

Front

What does it mean for angles to be adjacent?

Back

Angles that share a common side and a common vertex.

Front

What is the sum of angles in a triangle?

Back

The sum of the interior angles in a triangle is always 180 degrees.

Front

What is a reflex angle?

Back

An angle that measures more than 180 degrees but less than 360 degrees.