Using the law of cosine:
Cosine(angle) = Adjacent leg / Hypotenuse
You are given the angle, and the adjacent leg and need to solve for X, which is the hypotenuse.
Using the formula above you have:
Cosine(58) = 17 / x
Solve for x by dividing 17 by cos(58)
x = 17 / cos(58)
x = 32.08
What does x equal? In order to find the relationship between x and y we need to know both values at a given instance. For example, if x = 10 while y = 20/3, then we know that you = 20x/30 or 2x/3.