Scalene triangle - Definition and examples

A scalene triangle is a triangle with all three sides of different lengths.

Here are four ways to check if a triangle is scalene.

1. Close observation

After taking a  close look at the two triangles above, it is not hard to see that all three sides have different lengths.

2. The lengths of the sides are given.

3. Using tick marks.

Sides that have the same lengths will have the same number of tick marks. The triangle below is scalene since a different number of tick marks is used for each side.

4. The angles of the triangle are given.

If the angles of the triangle are all different, then the triangle is scalene.

For example, a triangle is scalene if the angles of the triangle are 40⁰,  60⁰, and 80⁰