Question 294613
Using Pythagoras
8^2 + (X + 6)^2 = (X + 8)^2
64 + X^2 + 12X + 36 = X^2 + 16X + 64
12X +36 = 16X
4X = 36
X = 9
Check sides are 8, 15, 17 which is a right-angled triangle