Triangle Base or Height Calculator
Find a triangle’s base or perpendicular height from its area and the other dimension.
Formula
Unknown base or height = 2 × area / known perpendicular dimension.
Triangle area: 12 cm² · Known base or height: 6 cm · Other dimension ≈ 2×(12 cm² × 0.0001 m²/cm²)÷(6 cm × 0.01 m/cm)×100
How to use
- Enter the triangle area and its unit.
- Enter the known base or its perpendicular height.
- Read the other dimension in cm.
Examples
- Area 12 cm² and base 6 cm give height 4 cm; area 12 cm² and height 4 cm give base 6 cm.
Frequently asked questions
How do I find the base?
Enter the area and the matching perpendicular height in the known-dimension field. The result is the base.
Can I enter a sloping side as the height?
No. The height must be perpendicular to the chosen base or its extension.
Does this work for an obtuse triangle?
Yes. The perpendicular foot can lie outside the triangle; area and the known dimension must be positive.
Sources
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