A window has a length of 45 inches and a diagonal of 53 inches What is the width of the window

Question

I don’t understand anything to do with math it’s very very stressful for me 

Answer 1

Note that the diagonal D is the hypotenuse of a right triangle, whose other sides are the width W and the length L.  Then

 

L² + W² = D² ⇒

 

W = √(D² - L²) = √(53² - 45²) inches = ? inches