Question 616018
If you can picture the tower and then the down slope of the hill. The angle between the tower and the slope of the hill is 90 + 19 = 109 (i.e. if the ground was flat the angle would be 90 but we have to add the slope of the hill. If the slope had been uphill then we would have taken away the 19 from 90.

We know the height of the tower and also the distance on the ground. If we picture the wire as making the third side of a triangle then we now have a triangle with two sides known and the angle between these known lengths and we are attempting to measure the third length opposite the known angle.

This is a problem where cosine is used to find the length of the side. Let us call the wire length x. Height of tower a, length on ground b and the angle opposite x as X.

The height of the tower is 212 and the length on the ground is 71.

So using the formula:

{{{x^2 = a^2 + b^2 - 2(a)(b)(cos X)}}}

{{{x^2 = 212^2 + 71^2 - 2*212*71*cos 109}}}

{{{x^2 = 59785.90}}}

x = 244.51 feet