Pythagorean theorem is a^2 + b^2 = c^2
2. You are trying to find x which is c^2
so plug in the other numbers to the other letters. 9^2 + 17^2 = c^2
9^2= 81. 17^2= 289
81 + 289 = 370
370= c^2
Now all you have to do is square root the number
*square root sign* 370
19.24
c = 19.24
So, x = 19.24