Types of triangles are defined based on similarity of their sides and angles.
Types based on Sides
Equilateral triangle has all the three sides with equal length.
Each angle is 60°.
Isosceles triangle has two sides with equal length.
Angles opposite to the equal sides are also same.
Scalene triangle has all sides with unequal length.
Angles of scalene triangle are also different.
Types based on Angle
Right Angle Triangle
Right angle triangle has one angle of 90°.
Side opposite to right angle is known as hypotenuse.
Acute triangle has all the angles measuring less than 90°.
Obtuse triangle has one angle measuring greater than 90°.