Triangle Area Calculator
Calculate the area of a triangle from its base and perpendicular height.
The height must meet the base at a right angle. Use the same unit for both values.
Data handling
Storage and export controls
- Retention
- The tool's working state is kept only while this page is open. Inputs and results are not saved to persistent storage by Got A Tool.
- Export
- The tool may prepare a result after you run it. It downloads or copies it only when you choose that action.
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How it works
Triangle Area Calculator: a practical guide
A triangle area calculator uses a triangle's base and perpendicular height to find its area. It keeps the required right-angle relationship visible instead of treating any two sides as if they were base and height.
- STEP 01
Choose one side to use as the base.
- STEP 02
Enter the perpendicular height from the opposite point to that base, using the same unit.
- STEP 03
Calculate to review one-half times base times height as square units.
What this tool does and its limits
Triangle area is one-half multiplied by base multiplied by perpendicular height. The height must form a right angle with the selected base; a slanted side is not automatically the height. This tool does not infer dimensions from a drawing, calculate missing sides or angles, use Heron's formula, convert units, or calculate non-triangular areas.
Inputs, selected files, and results stay in your browser. The tool does not upload them to Got A Tool or save them to persistent storage.
Questions
Triangle Area Calculator details
What is a perpendicular height?
It is the shortest straight distance from the opposite vertex to the base line, forming a 90-degree angle with that line.
Can I use a slanted side as height?
Only if it is perpendicular to the base you selected. A triangle's side length is often not its perpendicular height.
Why is the result in square units?
Area measures two dimensions. If base and height are both in centimeters, the result is in square centimeters.
Does this work for every triangle?
Yes when you know a base and its matching perpendicular height. Use a different method when you only know side lengths or angles.
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