Triangle Area Calculator
Classic half base times height formula for a triangle.
Inputs
Area
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Frequently asked questions
- What triangle area formula is used?
- For base and height: A = (base × height) / 2. Height must be perpendicular to the chosen base.
- Do I need all three sides?
- Not for this mode—base and perpendicular height are enough. Heron’s formula needs three sides (use another tool if listed).
- Can the height sit outside the triangle?
- For obtuse triangles the altitude may fall outside; the formula still uses perpendicular distance to the base line.
- What units does area use?
- Square units of the inputs (cm → cm²). Keep base and height in the same unit.