Answer:
90°
Step-by-step explanation:
∆GFD is an isosceles right triangle, so angle FDG is 45°. Segment DF bisects angle EDG, so that angle is 90°.
Arc AG is the other half of the semicircle AGE that includes 90° arc GE.
So, arc AG is 90°.
__
Comment on the problem
"a" and "b" are irrelevant to arc AG. They come into play for arc CE.
