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

If a triangle is made up of side lengths a, b and c

Given that c is the longest side length of the triangle,

The Pythagorean theorem can be used to tell if the triangle is obtuse, acute or right

In an obtuse triangle,

a^2 + b^2 < c^2

In an acute triangle,

a^2 + b^2 > c^2

In a right angled triangle,

a^2 + b^2 = c^2