Equilateral triangle calculator

An equilateral triangle has area √3 × side² ÷ 4 and height √3 × side ÷ 2.

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Side length

Answer

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An equilateral triangle has area √3 × side² ÷ 4 and height √3 × side ÷ 2.

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Precision and calculation record

Decimal places in numeric results and text downloads

Rounding changes displayed numbers, not the calculation. Text, fractions, matrices and CSV schedules keep their own formatting. Automatic keeps up to 12 significant digits, with money shown to cents where applicable.

Step-by-step calculation

Inputs are substituted below. Each line evaluates the next operation; intermediate values are displayed to 12 significant digits while the calculation uses full precision.

Saved scenario

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Formula and assumptions

All three sides are assumed equal. Zero gives a degenerate triangle. Area is in squared side-length units.

Automatic precision shows numbers to 12 significant digits. Thousands separators such as 1,000 are accepted; use a dot for decimals.

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Updated 2026-09-26

Using Equilateral triangle calculator

An equilateral triangle has area √3 × side² ÷ 4 and height √3 × side ÷ 2.

All three sides are assumed equal. Zero gives a degenerate triangle. Area is in squared side-length units.

Next: Basic calculator

A worked example

With side length = 4, the area is 6.928203230275509.

Before you use the result

All three sides are assumed equal. Zero gives a degenerate triangle. Area is in squared side-length units.

Example results for side length

These examples use the formula above. They are reference calculations, not recommended settings.

Side length	Area
2	1.73205080757
4	6.92820323028
8	27.7128129211

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