Question

Is it possible to determent if a triangle has a right angle if you have all the side lengths for the triangle?
If yes, please explain how.

Answer 1

Well, a right angle triangle will obey pythagoras' theorem while any other triangle will not.

Answer 2

If\[c^2=a^2+b^2\] (where c is the length of the longest side and a,b are the lengths of the other sides) holds, the triangle is a right angle triangle. If not, then not.