Question

An angle is equal to its supplement. Determine its measure.

Answer 1

Let required measure of angle = $x^0$
Then its supplement angle = ${180}^0-x$
$\therefore x={180}^0-x\Rightarrow x+x={180}^0$
$\Rightarrow 2x={180}^0\Rightarrow x=\frac{{180}^0}{2}={90}^0$
$\therefore$ Required angle = ${90}^0$