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 a right angle?

Back

A right angle measures 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 a missing angle in a triangle?

Back

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

Front

What is the measurement of the missing angle if one angle is 75 degrees and another is 45 degrees?

Back

The missing angle is 60 degrees (180 - 75 - 45 = 60).

Front

What is the measurement of the missing angle if one angle is 90 degrees and another is 30 degrees?

Back

The missing angle is 60 degrees (180 - 90 - 30 = 60).

Front

What is the measurement of angle x if angle y is 103 degrees?

Back

Angle x is 77 degrees (180 - 103 = 77).

Front

What is the measurement of angle x if angle y is 30 degrees?

Back

Angle x is 150 degrees (180 - 30 = 150).