Tri means three, and angle is for the angles! So, it means three angles!

A way to remember it

A Triangle is a closed, two-dimensional shape with three straight sides.

Definition

What is a Triangle?

Equilateral Triangle

​Definition

A triangle with all three sides as the same length.

Example:

15mm, 15mm, 15mm.

Isosceles Triangle

Definition

A Triangle that has two equal sides in length.

Example:

15mm, 15mm, 20mm.

Scalene Triangle

Definition

A Triangle with all of its sides different lengths.

Example:

15mm, 20mm, 25mm.

Now it's time to show what you learned!