Answer:
He should have done 8^2 + 15^2= x^2 because the hypotenuse is always the longest side and in Pythagorean theorem C represents the longest side
[tex] {x}^{2} = {(8)}^{2} + {(15)}^{2} [/tex]
[tex] {x}^{2} = 64 + 225[/tex]
[tex] {x}^{2} = 289[/tex]
[tex]x = \sqrt{289} [/tex]
[tex]x = 17[/tex]
