Question

Find the unknown angles in the given figures :

Answer 1

The given figure represents the isosceles triangle.

According to theorem of triangles,

angles opposite to equal sides are also equal.

So,

$b={40}^{\circ }$

According to angle sum property of the triangle,

$\begin{array}{c}b+{40}^{\circ }+a={180}^{\circ }\\ {40}^{\circ }+{40}^{\circ }+a={180}^{\circ }\\ a={100}^{\circ }\end{array}$

Thus,

$\begin{array}{c}a={100}^{\circ }\\ b={40}^{\circ }\end{array}$