Equilateral triangle

A equilateral triangle is a triangle with three equal sides and three equal angles of 60°.

Quick answer

A equilateral triangle is a triangle with three equal sides and three equal angles of 60°.

Main formula
Area = (√3/4)a².
Quick example
The perimeter is found by adding the three sides.

How to identify it

Look at the side lengths and angle measures. A clear sketch usually makes the classification immediate.

Main formula

Area = (√3/4)a².

Practice tip

When a height is not shown, draw it perpendicular to the base before calculating area.