Question

The supplementary angle of ${120}^o$ is:

• A. ${30}^o$
• B. ${50}^o$
• C. ${240}^o$
• D. ${60}^o$

Answer 1

The correct option is D ${60}^o$

Let the supplementary angle be $x$

Sum of supplementary angles is ${180}^{\circ }$

$\Rightarrow x+{120}^{\circ }={180}^{\circ }\Rightarrow x={180}^{\circ }-{120}^{\circ }\Rightarrow x={60}^{\circ }$