Question

Two angles are supplementary. The first angle measures 60°. What's the measurement of the second angle?

A. 180°
B. 30°
C. 90°
D. 120°

Answer 1

D

Explanation:

The sum of supplementary angles is 180°

To find the supplement of 60° subtract it from 180°, that is

second angle = 180° - 60° = 120° → D

Answer 2

Answer: Option D

120°

Explanation:

By definition it is said that two A and B angles are supplementary if the sum of A and B is equal to 180 °

In this case we know that one of the angles is 60 °

This is: A = 60 °

So to find the second angle we propose the following equation:

`60\° + B = 180\°`

Then we solve the equation for B.

`B = 180\°-60\°`

`B = 120\°`

So the second angle is 120 °

The answer is option D