Question

a side of the triangle below has been extended to form an exterior angle of 76°. find the value of x.

Explanation:

Step1: Apply exterior - angle theorem

The exterior - angle of a triangle is equal to the sum of the two non - adjacent interior angles. So, $x + 51^{\circ}=76^{\circ}$.

Step2: Solve for x

$x=76^{\circ}-51^{\circ}$.

Answer:

$25^{\circ}$