Question

Find the angle measure x in the following figures:

Answer 1

From the given quadrilateral three angles are ${40}^{\circ },{100}^{\circ }$, and ${140}^{\circ }$ We have to find the value of $x$, We know that the sum of four angles of a quadrilateral is equal to ${360}^{\circ }$.
$\begin{array}{c}\text{So,}{40}^{\circ }+{100}^{\circ }+{140}^{\circ }+x={360}^{\circ }\\ {280}^{\circ }+x={360}^{\circ }\\ x={360}^{\circ }-{280}^{\circ }\\ x={80}^{\circ }\end{array}$
Therefore, the value of $x$ is ${80}^{\circ }$.