we will test it by using the pythagorean theorem....if it works in the pythagorean theorem, then it is a right triangle
a^2 + b^2 = c^2....where a and b are the legs and c is the hypotenuse
24^2 + 17^2 = 40^2
576 + 289 = 1600
865 = 1600 (nope, not true)
so this is NOT a right triangle....false