Area of a Triangle Calculator
The base-height formula is A = ½ × base × height. If you know all three sides, Heron’s formula uses the semi-perimeter. Choose the method that matches the measurements you have.
Area20
Formula
A = ½bh. Heron: s = (a+b+c)/2, A = √[s(s−a)(s−b)(s−c)].
How to use this calculator
- Pick base-height or three sides.
- Enter the matching lengths.
- Read the area.
Examples
Base 8, height 5
Area = 20.
FAQ
Why is Heron NaN?+
The three lengths must be able to form a triangle (triangle inequality).
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