Triangle Area Calculator

Calculate triangle area from base and height or from three sides with Heron's formula.

Last updated: June 2026 | By Patchworkr Team

Base

Height

Math check: A = base x height / 2

Result

Enter the required values to calculate area.

Formulas

A = base x height / 2

s = (a + b + c) / 2

A = sqrt[s(s-a)(s-b)(s-c)]

Base 14 and height 12 gives area = 14 x 12 / 2 = 84.

For sides 13, 14, 15, semiperimeter s = 21 and Heron's formula gives area = 84.

Heron's formula only works when the three side lengths satisfy the triangle inequality.

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