Answer:

Explanation:
I will assume the following:
- You know how to use the quadratic formula
- You know how to simplify radicals
- You know how to use the pythagorean theorem.
The challenge of this exercise comes from using the pythagorean theorem and setting up a few equations.
Given that we have a segment 36 units long and another segment that is 16, it is trivial to get the other segment, 20. Additionally, there are two sides that I want to name so that way I can make a couple of substitutions. I will call these side a and side b. (see attachment 1)
Now comes with setting up three equations. I will start with the two smaller triangles, using side a and side b. See attachments 2 and 3.
Now with the big triangle. I will set up one last equation. See attachment 4.
Given what we know about attachment 2 and 3, we can make two substitutions. See attachment 5. I assume you know how to do the rest and arrive at your only real solution.