Answer:
∠EGF = 90°
Explanation:
Question is incomplete as the attachment is missing.
To solve this I'll make an assumption that ∠EGF is an angle inscribed in the circle.
Given that
Line EF is a diameter;
Then the arc formed by EF is 180° (semi circle).
The inscribed angle theorem states that an angle θ inscribed in a circle is half of the central angle 2θ that subtends the same arc on the circle.
So, the inscribed angle
Arc EF = 2 * ∠EGF
Make ∠EGF the subject of formula
∠EGF = ½ EF
∠EGF = ½ * 180°
∠EGF = 90°