Question

Three angles of a quadrilateral are equal and the measure of the fourth angle is ${120}^0$. Find the measure of each of the equal angles.

Answer 1

Sum of 4 angles of a quadrilateral ${360}^0$
One angles = ${120}^0$
$\therefore$ Sum of other three angles = ${360}^0-{120}^0={240}^0$
But each of these 3 angles are equal
$\therefore$ Each of equal angles = $\frac{{240}^0}{3}={80}^0$