Question

Determine whether a triangle with side lengths 6, 11, and 14 is acute, right, or obtuse.

Answer 1

A right triangle must obey the Pythagorean theorem, which is not the case here.

If the square of the largest side is less than the sum of the squares of the two smaller sides, the triangle is acute. If the square of the largest side is more than the sum of the squares of the two smaller sides, the triangle is obtuse. In this case, the latter sentence is true, so the triangle is obtuse.