Measuring Angles and Find the Missing Angle

Front

What is an angle?

Back

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

Front

What is the unit of measurement for angles?

Back

Angles are measured in degrees (°).

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

What is a straight angle?

Back

A straight angle measures exactly 180 degrees.

Front

How do you find the missing angle in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees. To find a missing angle, subtract the sum of the known angles from 180.

Front

If one angle measures 70 degrees and another measures 50 degrees, what is the measure of the third angle in the triangle?

Back

The third angle measures 60 degrees (180 - 70 - 50 = 60).

Front

What is a complementary angle?

Back

Two angles are complementary if their measures add up to 90 degrees.

Front

What is a supplementary angle?

Back

Two angles are supplementary if their measures add up to 180 degrees.