Pythagorean Inequality (Hinge Theorem Derivation) - Expii
Using the hinge theorem, we can adjust the Pythagorean theorem for different kinds of triangles. The sides on right triangles fit the relationship a² + b² = c², so acute triangles will fit a² + b² > c² with "c shorter," and obtuse triangles will fit a² + b² < c² with "c longer.".