Answer: Hello there!
We know that in a right triangle, the sum of the squares of the cathetus is equal to the square of the hypotenuse.
the smaller sides given are:
7ft and 12ft, and the longest is 17ft
so if this triangle is a right triangle, we should have that:
7^2 + 12^2 = 17^2
17^2 = 289
7^2 + 12^2 = 193
The terms are different, which means that this is not a right triangle, then the correct answer is B.