Question 612954
Use the pythagorean theorem (but in the opposite direction so to speak)


The idea is this: If A, B and C are the sides of a triangle where C is the longest side, then we can say the following


i) If A^2+B^2 = C^2 is true, then we have a right triangle


ii) If A^2+B^2 > C^2 is the case, then we have an acute triangle. 


iii) If A^2+B^2 < C^2, then we have an obtuse triangle.