Geometry & Measurement Calculators
Heron's Formula Calculator
Find a triangle's area from its three sides using Heron's formula, with worked steps.
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What is Heron's Formula?
Heron's formula gives a triangle's area from its sides alone: A = √(s(s−a)(s−b)(s−c)), where s is the semi-perimeter (a+b+c)/2.
How it works
We compute the semi-perimeter, substitute all four factors, and show each line of the calculation so the working is visible rather than only the final number.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
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