Finding Missing Angles

Front

What is an angle?

Back

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

Front

What is the vertex of an angle?

Back

The vertex is the point where the two rays of an angle meet.

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

How do you find a missing angle in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees. Subtract the sum of the known angles from 180 to find the missing angle.

Front

What is a right angle?

Back

A right angle measures exactly 90 degrees.

Front

What is an acute angle?

Back

An acute angle measures less than 90 degrees.

Front

What is an obtuse angle?

Back

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

Front

If one angle measures 30 degrees, what is the measure of its complementary angle?

Back

The complementary angle measures 60 degrees (90 - 30 = 60).

Front

If two angles are supplementary and one measures 120 degrees, what is the measure of the other angle?

Back

The other angle measures 60 degrees (180 - 120 = 60).