Question

"In the given figure, $\angle BAC$ is ${60}^{\circ }$" says Sita. Do you agree with her? Give reason.

Answer 1

By Exterior-angle theorem:In a triangle,the exterior angle is equal to sum of the interior opposite angles.

Here the exterior angle is ${125}^{\circ }$

By Exterior-angle theorem:$\angle BAC+\angle ABC={125}^{\circ }$

$\Rightarrow \angle BAC+{63}^{\circ }={125}^{\circ }$

$\Rightarrow \angle BAC={125}^{\circ }-{63}^{\circ }={62}^{\circ }\ne {60}^{\circ }$

Hence sita answer is wrong$={60}^{\circ }$