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

Explanation:

Step1: Recall exterior - angle property

The exterior angle of a triangle is equal to the sum of the two non - adjacent interior angles.

Step2: Set up the equation

Let the exterior angle be $76^{\circ}$, and the two non - adjacent interior angles be $51^{\circ}$ and $x$. So, $76^{\circ}=51^{\circ}+x$.

Step3: Solve for $x$

Subtract $51^{\circ}$ from both sides of the equation: $x = 76^{\circ}-51^{\circ}$. $x = 25^{\circ}$

Answer:

$25^{\circ}$