Question

21 find the measure of the \?\ or \x\.
? =

Explanation:

Step1: Recall the exterior angle theorem

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

Step2: Apply the theorem

In \(\triangle FGE\), the exterior angle \(\angle FGB\) (the angle marked with '?') is equal to \(\angle F+\angle E\). Given \(\angle F = 40^{\circ}\) and \(\angle E=40^{\circ}\).
So, \(\angle FGB=40^{\circ}+40^{\circ}\)

Answer:

\(80\)