This is a simple Pythagoras' theorem problem. If the length of the right angled triangle is 15ft and its width is 8ft, then its hypotenuse (x, the diagonal or the length of the pipe in this case) will be:
[tex]x = \sqrt{ {8}^{2} + {15}^{2} } \\ x = \sqrt{64 + 15} \\ x = \sqrt{289} \\ x = 17[/tex]
Therefore, your answer is B. The length of the pipe will be 17 feet.
