What are the Different Types of Triangles?

Triangles can be classified according to the lengths of their sides and the measures of their angles:

By Side Length

  • Scalene: All three sides are different lengths.
  • Isosceles: Two sides are the same length.
  • Equilateral: All three sides are the same length.

 

By Angle Measure

  • Acute: All three angles are less than 90 degrees.
  • Right: One angle is 90 degrees.
  • Obtuse: One angle is greater than 90 degrees.

types triangles

The following table summarizes the different types of triangles:

Side Length

Angle Measure

Example

Scalene

Acute

scalene

Isosceles

Right

right triangle

Equilateral

Obtuse

equilateral

Another summary of Triangles classified by side length and angle measure.

types of triangles