# Obtuse Triangle

Triangles are classified according to the angle measures or according to side lengths. Triangles are classified based on angle measures as acute, obtuse and right triangles. Any triangle should have at least two acute angles to comply with angles sum property of a triangle.

An obtuse triangle hence has one obtuse angle, the other two angles being the required acute angles. We can define an obtuse triangle as a triangle one of whose angle measure is greater than 90º and the sum of the measures of other two angles is less than 90º.

If Δ ABC is a obtuse triangle with C as the obtuse angle then the measure of $\angle$C > 90º and measure of $\angle$A + measure of $\angle$B < 90º.