Types of Triangles - Lessons
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.
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Lesson 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:
- Acute triangle
- Right triangle
- Obtuse triangle
- Isosceles triangle
- Equilateral triangle
- Scalene triangle
You can learn more about these triangles in the lessons below.
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Introduction Video
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Interact and have fun learning of the types of triangles by downloading our Zapzapmath Home Grade 4 app and playing Shape Detective:
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Google Play (Android)
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.
Topic Lessons
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Acute Triangle
In this lesson, we will learn about acute triangles...
-
Right Triangle
In this lesson, we will learn about right triangles...
-
Obtuse Triangle
In this lesson, we will learn about obtuse triangles...
-
Isosceles Triangle
In this lesson, we will learn about isosceles triangles...
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Equilateral Triangle
In this lesson, we will learn about equilateral triangles...
-
Scalene Triangle
In this lesson, we will learn about scalene triangles...