Shapes are part of our daily life and it is important to understand each and every shape. The most common shape we see around is the triangle. The shape with three corners are commonly known as the triangle but every three-cornered shape is not the same, and to understand this concept we are here to explain you with different types of triangles.

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## Triangle and Types of Triangles

Triangle is a three-sided polygon. This closed figure consists of three lines which are linked at the endpoint to each other. The main properties of the triangle are that the sum of the interior angle of the triangle will be 180° and the sum of the exterior angles will be 360° always. Triangle can be classified according to their sides and interior angles. Following are the details about each qualification.

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## Types of Triangles with Respect to Sides

### Equilateral Triangle

This type of triangle consists of three equal sides and equal angles. Every side of the triangle is of the same length and every angle will be of the same measure of 60°. The following figure is an equilateral triangle –

### Isosceles triangle

The triangle with only two equal sides is known as the isosceles triangle. Not only two equal sides, the isosceles triangle also consists of two equal angles. The following figure is of the isosceles triangle-

### Scalene Triangle

The triangle with no equal sides is the scalene triangle. Each line of this triangle is of different length. Following is the figure of the scalene triangle:

## Types of Triangles with Respect to Angles

### Right Triangle

This triangle consists of one right angle and two acute angles. The right angle is an angle which measures 90 degrees and the acute angles are those angles which measure less than 90 degrees. Thus Right triangle is a triangle with one angle of 90° and the other two angle that measures less than 90°are acute angles. The right triangle is an angle with one 90° angle and two less than 90° angles. The following figure shows the right triangle-

### Obtuse Triangle

This is a triangle with two acute angles and one obtuse angle. The acute angle is those angles which measure less than 90° whereas the obtuse angle is those angle which measures above 90°. Therefore, an obtuse triangle is a combination of two acute angles and one obtuse angle.

### Acute Triangle

An acute triangle is a triangle which consists of three acute angles. This is the triangle which consists of three angles all of below 90°.

### Equiangular triangle

An equiangular triangle is an angle with equal angles. Every angle of this triangle measures the same degrees.

When we learn about the various types of triangle, we keep in mind the measurement of sides and angles. The above classification will now make it easier for you to differentiate between triangles. Now every triangle is not just a triangle for you. You can now easily differentiate between the shapes of the triangle as whether it is a right triangle or an equilateral triangle.

## Solved Question for You

**Question 1: An equilateral triangle can also be called an acute angle, why?**

**Answer:** All the three sides and angles of an equilateral triangle are equal. We know that the sum of angles in a triangle is 180°. Since all the three angles in an equilateral triangle are equal, we write it as:

∠A + ∠B +∠C = 180

Now, ∠A = ∠B = ∠C, hence the sum of three angles can be written as ∠A + ∠A + ∠A = 3 ∠A

3 ∠A = 180°

∠A = 180/3

= 60°

Since all the angles in an equilateral triangle are equal, we get, ∠A = ∠B = ∠C = 60°

**Question 2: What are the types of triangles with respect to the angles?**

**Answer:** When we look at the different types of triangles on the basis of angles, they are of 5 types. They are Right Triangle, Obtuse Triangle, Acute Triangle, and Equiangular Triangle.

**Question 3: What is an Equilateral Triangle?**

**Answer:** An equilateral triangle is a kind of triangle which comprises of 3 equal sides and equal angles. Moreover, each side of this triangle is of the same length and every angle is going to be of the same measure which is 60°.

**Question 4: Give the definition of a triangle.**

**Answer:** A triangle is a three-sided polygon which is a close figure consisting of 3 lines that link at the endpoint to each other. The major properties of a triangle are that they are the sum of the interior angle of the triangle is going to be 180°. Similarly, the sum of the exterior angles is always going to be 360°. Further, we can classify triangles on the basis of their sides and interior angles.

**Question 5: Define an obtuse triangle.**

**Answer:** An obtuse triangle is one having two acute angles and one obtuse angle. You must know that an acute angle is ones which measure less than 90° while the obtuse angle one is one which measures over 90°. Thus, an obtuse triangle refers to a combination of 2 acute angles and 1 obtuse angle.

Then what about complete angle?