How to tell if a triangle is right obtuse or acute with side lengths?

Using Pythagorean theorem we can easily get to know about the triangle.

If c^2=a^2 + b^2 Then triangle is Right Angled.

If c^2 > a^2 + b^2 Then triangle is obtuse triangle

and when c^2 < a^2 + b^2, it means triangle is acute triangle.

(Here a = adjacent, b = opposite and c=hypotenuse of triangle)