Question

Two angles of a quadrilateral are ${70}^{\circ }$ and ${130}^{\circ }$ and the other two angles are equal. Find the measure of these two angles.

Answer 1

$A$ and $B$ be $x$,(Given two angles are same)
$C=$${70}^{\circ }$ and $D=$${130}^{\circ }$
$\angle A$ + $\angle B$ + $\angle C$ + $\angle D$ = ${360}^{\circ }$ (Sum of all the angles of a quadrilateral is ${360}^o$)
$x+x+{70}^{\circ }+{130}^{\circ }={360}^{\circ }$
$2x={360}^{\circ }-{200}^{\circ }$
$2x=160$
$x$ = $\frac{{160}^{\circ }}{2}$ = ${80}^{\circ }$
$A={80}^{\circ }$ and $B={80}^{\circ }$