Point F is on circle C.
Circle C is shown. Line segments E C, F C, and D C are radii. Tangents E G and D G intersect at point D outside of the circle. A line is drawn to connect points F and G. The length of G E is 10 and the length of E C is 7.5. Angles E and D are right angles.
What is the length of line segment GF?
12.5 units
15.0 units
17.5 units
20.0 units
