Equilateral Triangle Calculator

About this calculator

This calculator finds an equilateral triangle's area using A = (√3/4)·s², its height using h = (√3/2)·s, and its perimeter as 3s — all three derived from the Pythagorean theorem applied to the two 30-60-90 right triangles formed when the equilateral triangle is bisected down its center.

Geometry students verifying homework, engineers and designers working with triangular trusses, signage, or tiling patterns, and hobbyists in woodworking or origami who need precise triangle dimensions use this. Enter the side length to get the area, height, and perimeter.