Equilateral triangle calculator

Please enter one property of the equilateral triangle

Use symbols: a, h, T, p, r, R


An equilateral triangle is a triangle where all three sides have the same length, and all three angles are also congruent and measure 60 degrees each.

If you know the length of one side of an equilateral triangle (a), you can use that information to find the perimeter (p) of the triangle: p = 3a

You can also use the side length to find the area of the triangle using the formula:

Area = (√3/4) * a2

You can also use the side length to find the height (h) or the inradius (r) of the triangle:

h = (a√3)/2
r = a/(2√3)

If you know the area of an equilateral triangle, you can use that information to find the length of one side (a) using this formula:
Area = (√3/4) * a2

You can also use the area to find the height (h) or inradius (r) of the triangle:

h = (2 * √(3 * area))/a
r = √((2 * area)/√3)

If you know the height (h) of an equilateral triangle, you can use that information to find the length of one side (a) using this formula:

a = (2 * h)/√3

Calculate an equilateral triangle by:

An equilateral triangle in word problems in mathematics:



more triangle problems »

Look also at our friend's collection of math problems and questions:

See more information about triangles or more details on solving triangles.