Question 330349
Use the Pythagorean Theorum a^2 + b^2 = c^2.

Draw a triangle, label two sides a & b.  Label the long side (hypotenuse) c.

Let a be the legnth of the pole, 21'.

let b be the distance along the ground, 14'.

substitute values into the equation and get 21^2 + 14^2 = c^2.

reduce 441+196 = c^2

reduce 637 = c^2

take the square root of both sides and c, the legnth of the guy wire is 25.2388'.