## The Lesson

A scalene triangle is a triangle where none of the sides or angles are equal.**Note:**The lines through the two sides of the triangle in the image above indicate they are of equal length. The two arcs indicate the two angles are equal.

## Dictionary Definition

The Merriam-Webster dictionary defines a scalene triangle as "having the three sides of unequal length."## Real Examples of Scalene Triangles

Below are real examples of scalene triangles.In each case

- No sides are the same length.
- No angles are the same (60°).

## What's in a Name?

'Scalene' comes from the Greek word "skalenos", meaning 'unequal'.## Interior Angles of a Scalene Triangle

The interior angles of any triangle add up to 180°. In a scalene triangle, the angles are all different.## Symmetry of a Scalene Triangle

A scalene triangle has no lines of symmetry.## Interactive Game on the Types of Triangle

**the types of triangle**.