# Equilateral Triangle Calculator

Calculate an equilateral triangle. This is the simplest regular polygon (a polygon with equal sides and angles). Enter one of the known values. Then click calculate.

**Enter one of the known values of an equilateral triangle**

**Side length (a=b=c)**

**Height (h)**

**Perimeter (p)**

**Square (S)**

**The radius of the circumscribed circle (R)**

**Radius of the inscribed circle (r)**

## Formulas

h = √3/2 * a

р = 3 * а

S = a2 * √3 / 4

R = √3 / 3 * a

r = √3 / 6 * a

All angles are equal to each other and equal to 60°

The side length, height, perimeter and radius have the same unit of measurement (for example, a centimeter), the area has the same unit of measurement squared (for example, a square centimeter).