Answer:
Angle AGF and FGD are complimentary angles meaning they add up to 90 degrees. Since AGF is 77 and the total angle AGD is 90, we can solve for angle FGD. 90-77=FGD. Angle FGD is 13 degrees. Now angle EGC or simply angle x, is vertical angles with angle FGD. So that means they are the same angle measure. Since FGD is 13, x is also 13
Explanation: