Scalene Triangle

Lesson Objective

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

Study Tips

Tip #1

When a triangle has three sides (edges) of different lengths, this triangle can be called a scalene triangle. See some examples below:

Tip #2

Since this type of triangle has three sides of different lengths, all of its internal angles will be different as well. See the picture below:

The math video below will explain more...

Math Video

Lesson Video

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Math Video Transcript

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In this lesson, we will learn about scalene triangle (ST).

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A triangle is a ST, when all the sides of the triangle, have different lengths..

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Now, to demonstrate this, let's move vertex 'C' to the left.

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Here, we can see that, all the 3 sides of this triangle have different lengths. Hence, this is a ST.

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It is important to note that, the interior angles will also be different.

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Let's continue to move point ‘C’.

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Now, when these two sides have the same length, it is not a ST.

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As we continue to move 'C', we will get a right triangle.

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A right triangle, can also be a ST, when the length of each side is different.

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However, it will not be a scalene, if two of its sides, have the same length.

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Let's see some examples.

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Is this a ST?

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Since this triangle has 3 sides of different lengths, this is a ST.

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Next example. How about this triangle?

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We can see that, these angles are not the same.

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This means that, these 3 sides must have different lengths.

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Hence, this is a ST.

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Last example. Now, these 2 sides have the same length.

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Therefore, this is not a ST.

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That is all for this lesson.

Practice Questions & More

Multiple Choice Questions (MCQ)

Now, let's try some MCQ questions to understand this lesson better.

You can start by going through the series of questions on scalene triangles or pick your choice of question below.

Question 1

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