Option C:
The measure of arc GH is 45°.
Solution:
Given data:
m∠GFH = 22.5°
To find the measure of arc GH:
By inscribed angle theorem,
The measure of an inscribed angle is equal to the half of the measure of the intercepted arc.


Multiply by 2 on both sides, we get


Switch the sides.
m(arc GH) = 45°
The measure of arc GH is 45°.
Option C is the correct answer.