Solve the Problem $20 \mathrm{yd}$ Long and Touches the Ground $15 \mathrm{yd}$

Solve the problem.
-The diagram below shows a rope connecting the top of a pole to the ground. The rope is $20 \mathrm{yd}$ long and touches the ground $15 \mathrm{yd}$ from the pole. How tall is the pole? Round approximations to the nearest tenth.

A) 87.5yd
B) $17.5 \mathrm{yd}$
C) $6.6 \mathrm{yd}$
D) $13.2 \mathrm{yd}$