# Obtuse angled triangle explained

Learn and know what does obtuse angled triangle means in geometry. In math, we will study about triangles and classification of triangles.

Triangles are classified mainly based on sides and angles, and in each case we have three different triangles. Obtuse angled triangle comes in classification of triangles based on angles. Now we will learn the definition of obtuse angled triangle and we will see how it looks like.

## What is triangle?

A simple and easy definition of triangle is “A simple closed figure bounded by 3 line segments is called as a triangle”. (or) a polygon is a triangle if it is made up of three line segments.

### What is obtuse angled triangle?

Before knowing obtuse angled triangle, we will know what is obtuse angle in types of angles. Obtuse angle means the angles which are in between 90 degrees to 180 degrees. Obtuse angle triangle is if in a triangle out of three angles any one angle is obtuse angle then the triangle is called as an obtuse angle triangle.

Examples:

• ${ 120 }^{ 0 }$, ${ 40 }^{ 0 }$ and ${ 20 }^{ 0 }$ be the three angles of a triangle. Out of these three angles one angle is obtuse. So we call as an obtuse triangle.
• ${ 80 }^{ 0 }$, ${ 70 }^{ 0 }$ and ${ 30 }^{ 0 }$ are the three angles of a certain triangle. Now can you say this triangle as obtuse triangle? No, the triangle with these angles is not a obtuse triangle because all are acute angles only, no obtuse angle here.
• ${ 99 }^{ 0 }$, ${ 41 }^{ 0 }$ and ${ 40 }^{ 0 }$ are the angles of a triangle. Is this triangle is obtuse? As one angle is obtuse so definitely it is a obtuse triangle only.
• ${ 100 }^{ 0 }$, ${ 50 }^{ 0 }$ and ${ 70 }^{ 0 }$ is obtuse triangle? Observe all the angles the sum we are getting ${ 220 }^{ 0 }$. We know that sum of angles should be exactly ${ 180 }^{ 0 }$ but we are getting more than that. So forget about obtuse triangle or not first of all this is not a triangle. With the given angles we can’t draw a triangle.