Question

Find the magnitude of an angle, which is $\frac{2}{3}$ of its supplement.

Answer 1

Let the angle be $x$ then its supplement is given to be $\frac{2x}{3}$.

Then,

$x+\frac{2x}{3}={180}^o$

or, $\frac{5x}{3}={180}^o$

or, $x={108}^o$.

The required angle is ${108}^o$.