Step-by-step explanation:
I assume that DF and DQ are tangents to the circle.
angle FGQ = 268°
therefore, angle FQ = 360 - 268 = 92°
b = 1/2 × (angle FGQ - angle FQ) = 1/2×(268 - 92) =
= 1/2 × 176 = 88°
