Answer:
x = 15
Explanation:
We assume you want to find the value of x.
Know (or prove) that in this geometry, all of the right triangles are similar. That means the ratios of corresponding sides are proportional.
short side / hypotenuse = 9/x = x/25
x^2 = (9)(25) . . . . . . . . . . multiply by 25x ("cross multiply")
x = √((9)(25)) = (3)(5) . . . take the square root
x = 15