Question

The measure of angle which is equal to its supplement is

• A. ${100}^{\circ }$
• B. ${90}^{\circ }$
• C. ${120}^{\circ }$
• D. ${40}^{\circ }$

Answer 1

The correct option is B

${90}^{\circ }$

We know that,

If 2 angles are supplementary, their sum is ${180}^{\circ }.$

Let one of the angle be $x^{\circ }$

Then another angle is also $x^{\circ }(\because$ They are equal).

$\Rightarrow x^{\circ }+x^{\circ }={180}^{\circ }$

$\Rightarrow 2x^{\circ }={180}^{\circ }$

$\Rightarrow x^{\circ }={90}^{\circ }$