Question

A triangle has sides with lengths of 56 millimeters, 80 millimeters, and 96 millimeters. Is it a right triangle?

Answer 1

No. For a right triangle the largest side squared must equal the sum of the squares of the other two. Here 96^2 = 9216, while 56^2 + 80^2 = 3136 + 6400 = 9536, so 96^2 ≠ 56^2 + 80^2. Because 96^2 < 56^2 + 80^2 the triangle is acute, not right.