HOW DO I SOLVE THIS PLEASE HELP

Answer:
64
Step-by-step explanation:
Euclide's theorem states that in a right triangle, the square built of the side lenght is equivalent of the rectangle with sides hypotenuse and projection of the same side lenght. In formula, given the measures on the triangle:
[tex]60^2 = (36+x)(36) \rightarrow 3600 = 36(x+36) \rightarrow 100=x+36\\ x=64[/tex]