You can put this solution on YOUR website! If we were to draw a picture we would see that we have a right-angled triangle.
This means we can use Pythagorean Theorem to determine the length of the diagonal (which in our case is the hypotenuse).
To eliminate the square, we must take the square root of both sides leaving:
This is around 144.22. Therefore the diagonal is around 144.22 yards in length.