Free Triangle Calculator
Area, perimeter, and heights from three sides (Heron's formula).
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Inputs
Result
Area
6.0000
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Short answer
Area, perimeter, and heights from three sides (Heron's formula).
What is the Triangle Calculator?
Area, perimeter, and heights from three sides (Heron's formula).
How does the Triangle Calculator work?
Enter the inputs above and read the result.
Formula
Variables
a,b,cSide lengthssSemi-perimeter
Explanation
Heron's formula; angles from the Law of Cosines.
Examples
Applications
Advantages
Limitations
Common mistakes
Tips
Related concepts
The Triangle Calculator sits inside the Math Calculators hub, in the geometry & shapes cluster. Length, area, volume and angle in two and three dimensions. Understanding the terms below makes the output easier to interpret and easier to compare against neighbouring measures.
Practical use cases and industry applications
Understanding Triangle
Area, perimeter, and heights from three sides (Heron's formula). Within math calculators, triangle belongs to the geometry & shapes cluster, where it shares terminology and assumptions with closely related tools.
Learning how triangle is calculated
Heron's formula; angles from the Law of Cosines. Working through the variables one at a time — a,b,c, s — makes the result reproducible by hand and easier to sanity-check.
Using triangle to make a decision
Because outputs depend on the assumptions you enter, run more than one scenario before committing to a figure.
How triangle compares with related measures
area, perimeter, volume, surface area all describe adjacent aspects of geometry & shapes. Comparing this calculator's output against those measures — using the related tools listed on this page — prevents a single metric from being read in isolation.
Frequently asked questions
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