Answer:
The measure of an inscribed angle is half the measure of the intercepted arc
∠EFG creates Arc EDG
if ∠EFG is 1/2 arc EDG then 115° x 2 = 230°
A circle is 360°.
The remaining arc EFG is 360° - 230° = 130°
∠EDG is 1/2 of arc EFG so, 130° ÷ 2 = 65°
∠EDG = 65°