Chapter 4.5, Problem 1ST2

To determine

To find the value of $x$ from the given figure

  

Answer to Problem 1ST2

The value of $x={70}^{\circ }$ .

Explanation of Solution

Given information :

Givenfigure

  

Since opposite to congruent sides are congruent angles.

So, $x^{\circ },x^{\circ },{40}^{\circ }$ be three angles of given triangle.

Thus, $x+x+40=180$ .

  $\begin{array}{l}\Rightarrow 2x+40=180\\ \Rightarrow 2x=180-40\\ \Rightarrow 2x=140\\ \therefore x={70}^{\circ }\end{array}$

Hence, the value of $x={70}^{\circ }$ .