Question

A triangle has side lengths of 7, 24, and 25. Is the triangle right, acute, or obtuse?

Answer 1

I think that it's an obtuse triangle. 

Answer 2

If the squares of the shorter sides added together are:

Equal to the square of the longest side - the triangle is right angled
Less than the square of the longest side - the triangle is obtuse angled
More than the square of the longest side - the triangle is acute angled

This example would be right, which comes from the Pythagoras theorem