Calculate the area, perimeter, and missing side of a triangle using base and height, or three sides.
Triangle Calculator
Math
Inputs
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Enter all three side lengths.
Click Calculate to get area, perimeter, and all angles.
Uses Heron's formula for area: Area = √(s(s-a)(s-b)(s-c)) where s is the semi-perimeter. Angles are calculated using the Law of Cosines.
Heron's formula calculates triangle area knowing only the three side lengths: Area = √(s(s-a)(s-b)(s-c)) where s = (a+b+c)/2.