Triangle
Calculate a triangle’s perimeter and area from its three side lengths.
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Use the same unit for all sides. Each pair of sides must add up to more than the third side. Area is calculated with Heron’s formula. Change the input or settings to update your result. Results update as you type. Up to 1,000,000 characters.
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How to use Triangle
- Enter the values you want to calculate and choose the relevant units or settings.
- The result updates as you type. Adjust the available settings if needed.
- Review the result, then use Copy result or a download link when available.
What to expect
Calculate a triangle’s perimeter and area from its three side lengths. Use the same unit for all sides. Each pair of sides must add up to more than the third side. Area is calculated with Heron’s formula.