Question 323704
The length of the pole and the distance from the pole to the point on the ground are legs of a right triangle.
The hypotenuse of the right triangle is the length of the wire.
Use the Pythagorean theorem,
{{{H^2=A^2+B^2}}}
{{{H^2=14^2+21^2=7^2(2^2+3^2)}}}
{{{H^2=7^2(13)}}}
{{{H=7sqrt(13)}}}ft
or approximately
{{{H=25.2}}}ft