Chapter 11.4, Problem 6PPS

To determine

To find the missing angles in the given quadrilateral.

Answer to Problem 6PPS

$x={81}^{\circ }$ & missing angle is ${81}^{\circ }$ .

Explanation of Solution

Given:

Concept used:

The sum of all the interior angles of a quadrilateral is ${360}^{\circ }$ .

Calculation:

Since the sum of all the interior angles of a quadrilateral is ${360}^{\circ }$ , therefore we get

  $\begin{array}{l}\Rightarrow {90}^{\circ }+{90}^{\circ }+x^{\circ }+{99}^{\circ }={360}^{\circ }\\ \Rightarrow x^{\circ }+{279}^{\circ }={360}^{\circ }\\ \Rightarrow x^{\circ }={360}^{\circ }-{279}^{\circ }\\ \Rightarrow x^{\circ }={81}^{\circ }\end{array}$

Therefore missing angle is,

  $x={81}^{\circ }$