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Let's learn the types of triangle:

Triangles can be classified based on its sides as well as its angles.

Types of triangles based on its side lengths are as follows.

- Equilateral triangle
- Isosceles triangle
- Scalene triangle

A triangle is an equilateral when all its sides are equal in length.

Example:

In here, the sides are equal in measure \(AB=BC=CA=5\) units.

A triangle is isosceles when two of its sides are equal in length.

Example:

In here, the two of the sides are equal in measure \(AB=CA=1\) unit and \(BC=√2\) units.

A triangle is a scalene when all the three sides are unequal.

Example:

In here, all the sides are unequal in measure \(AB=7.7, CA=5\) units and \(BC=9\) units.

Types of triangles based on its angles are as follows.

- Acute angled triangle
- Right angle triangle
- Obtuse angled triangle

A triangle is acute angle triangle when all the three of its angle are acute (less than 90°).

Example:

In here, all the three angles are less than \(90°\). That is, \(∠A=60°, ∠B=50°\) and \(∠C=70°\).

A triangle is right angle triangle when one of its angles is a right angle (90°), and the other two are acute angles (less than 90°).

Example:

In here, one among the angle is \(90°\), and the other two are acute. That is, \(∠A=40°, ∠B=50°\) and \(∠C=90°\).

A triangle is an obtuse angle triangle when one of its angles is an obtuse angle (greater than 90°), and the other two are acute angle (less than 90°).

Example:

In here, one among the angle greater than \(90°\) and the other two are acute. That is, \(∠A=120°, ∠B=35°\) and \(∠C=25°\).