Answer:
B
Explanation:
assuming DF is the diameter of the circle , then
the angle in a semicircle is 90° , that is
∠ DCF = 90° and Δ CDF is a right triangle
using Pythagoras' identity in the right triangle
CD² + CF² = DF²
CD² + 60² 65²
CD² + 3600 = 4225 ( subtract 3600 from both sides )
CD² = 625 ( take square root of both sides )
CD =
= 25