Question

Tick ($\surd$)the correct answer in each of the following:

If an angle is twice its supplement, what is the angle?

• A. (a)$30°$
• B. (b)$60°$
• C. ©$90°$
• D. (d)$\angle 120°$

Answer 1

The correct option is D

(d)$\angle 120°$

Supplementary angles are angles whose sum is equal to $180°$

Let one supplementary angle be $x$

Then,angle is twice its supplement$=2x$

Then, $$\begin{gathered} 2x+x=180° \\ 3x=180° \\ x=\frac{180°}{3}=60° \end{gathered}$$

$2x=2\times 60°=120°$

Hence,angle twice its supplement is $120°$.