The answer would be 17. This is because, the format for finding out the hypotenuse of a triangle is-- a^2 + b^2 = c^2 So, it would translate to-- 15^2 + 8^2 = c^2 225 + 64 = 289 Because 289 = c^2, you need to take the square root of it. The square root of 289 is 17. Therefore, your answer is 17.