Question

Point F is on circle C.

Answer 1

 CF is a radius = 7.5 units

To find GC we will use the Pythagorean theorem.GC² = 10² + 7.5²

GC² = 100 + 56.25GC² = 156.25GC = √ 156.25GC = 12.5

GF = 12.5 + 7.5 = 20

Answer:  20 units

Answer 2

Answer

Find out the length of line segment GF .

To prove

In Δ GEF is a right triangle .

As shown in the diagram

GE = 10 units

EC = 7.5 units

By using the pythagorean theorem

Hypotenuse² = Perpendicular² + Base²

GC² = GE² + EC²

      =  10² + 7.5²

      = 100 + 56.25

      = 156 .25

$GC = \sqrt{156.25}$

GC = 12 .5 units

As shown in the diagram

CF is the radius of a circle .

CF = 7.5 units (As in the figure EC = 7.5 units)

GF = GC + CF

       =  12 .5 units + 7.5 units

      =  20 units

Therefore option (d) is correct .

Hence proved