On the basis of length of the sides, triangles are classified into three categories:
- Scalene Triangle
- Isosceles Triangle
- Equilateral Triangle
On the basis of measurement of the angles, triangles are classified into three categories:
- Acute Angle Triangle
- Right Angle Triangle
- Obtuse Angle Triangle
Scalene Triangle
A scalene triangle is a type of triangle, in which all the three sides have different side measures. Due to this, the three angles are also different from each other.

Isosceles Triangle
In an isosceles triangle, two sides have equal length. The two angles opposite to the two equal sides are also equal to each other.

Equilateral Triangle
An equilateral triangle has all three sides equal to each other. Due to this all the internal angles are of equal degrees, i.e. each of the angles is 60°

Acute Angled Triangle
An acute triangle has all of its angles less than 90°.

Right Angled Triangle
In a right triangle, one of the angles is equal to 90° or right angle.

Obtuse Angled Triangle
An obtuse triangle has any of its one angles more than 90°.
