Introduction

This page contains the list of lessons on types of triangles. It also gives you a quick introduction on triangles. Each lesson consists of a math video, study tips and practice questions.

Sponsored Links

Lessons Description

A triangle is a polygon with three vertices and three sides (edges). It has three internal angles. When we add all the internal angles together, we will definitely get 180°.

The video below will give you a quick introduction to the following types of triangles:

1. Acute triangle
2. Right triangle
3. Obtuse triangle
4. Isosceles triangle
5. Equilateral triangle
6. Scalene triangle

You can learn more about these triangles in the lessons below.  

Introduction Video

Math Video Transcript

00:00:03.230 This video is an introduction to types of triangles. 00:00:09.070 A triangle is a polygon, with 3 vertices, and 3 sides. 00:00:17.120 Now, let's have a quick look, at the different triangles. 00:00:23.100 We will learn the details in the upcoming lessons. 00:00:27.240 Now, if we classify triangles by internal angles, this triangle will be an acute triangle. 00:00:35.150 Now, when I move this vertex to the left, we can see that this triangle becomes a right triangle, when the angle at vertex B is 90 degrees. 00:00:47.240 As we move vertex 'A' further to the left, this triangle becomes an obtuse triangle. 00:00:55.180 Now, let's classify triangles, by relative lengths of sides. 00:01:02.000 Let's move this vertex. When this triangle has 2 sides of equal length, it is called an isosceles triangle. 00:01:16.230 Next, if all the sides of the triangle have the same length, it is an equilateral triangle. 00:01:25.050 Let's move the vertex ‘A’ around. Alright, if none of the sides of the triangle have the same length, it is called a 'scalene' triangle. 00:01:39.190 That is all for the introduction. The lessons below will explain these triangles in detail.

In this lesson, we will learn about acute triangles...

Acute Triangle

In this lesson, we will learn about right triangles...

Right Triangle

In this lesson, we will learn about obtuse triangles...

Obtuse Triangle

In this lesson, we will learn about isosceles triangles...

Isosceles Triangle

In this lesson, we will learn about equilateral triangles...

Equilateral Triangle

In this lesson, we will learn about scalene triangles...

Scalene Triangle