Answer and Step-by-step explanation:
31 degrees on the top would be equal to the angle in between x and 600ft, by the interior angles theorem.
That means we can solve for y using the trigonometric function of tangent.

Multiply by 600 to both sides, then use a calculator to solve.
600(tan(31)) = x
x = 360.5163714
x ≈ 360.5 is the answer.