Question

A quadrilateral has three acute angles, wach measuring ${75}^0$. Find the measure of the fourth angle.

Answer 1

Three acute angles of a quadrilateral are ${75}^0$ each
$\therefore$ Sum of three angles = $3\times {75}^0={225}^0$
But sum of angles = ${360}^0$
$\therefore$ Fourth angle = ${360}^0-{225}^0={135}^0$