Angles and Angle Relationships

Front

What is an angle?

Back

An angle is formed by two rays (sides) that share a common endpoint (vertex).

Front

What is the measure of a right angle?

Back

A right angle measures 90 degrees.

Front

What is a straight angle?

Back

A straight angle measures 180 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 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.

Front

If one angle measures 36°, what is the measure of its complementary angle?

Back

54° (because 36° + 54° = 90°).

Front

If one angle measures 108°, what is the measure of its supplementary angle?

Back

72° (because 108° + 72° = 180°).

Front

What is the sum of the angles in a triangle?

Back

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