OBTUSE TRIANGLE A triangle whose one angle is obtuse is called an obtuse-angled triangle or an obtuse triangle.

An obtuse angle is

An obtuse angle is

Write the sum of the angles of an obtuse triangle.

A triangle whose one angle is more than 90^(@) is called a scalene triangle (b) a right triangle an acute triangle (d) an obtuse triangle

A right triangle cannot have an obtuse angle.

Classify these triangles as right, acute or obtuse angled triangle.

Acute Angle; Right Angle and Obtuse Angle

If the sides of a triangle are 3,5, and 6, prove that the triangle is obbtuse - angled triangle and find the obtuse angle.

Define each of the following: (a) A scalene triangle (b) An obtuse triangle