Triangle Area Calculator
Find triangle area from base/height, two sides + angle, or three sides (Heron's formula).
Inputs
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Area
Enter values and click calculate.
Triangle area formulas
• Base × height: Area = ½ · b · h
• SAS: Area = ½ · a · b · sin C
• Heron's formula: Area = √[s(s−a)(s−b)(s−c)], where s = (a+b+c)/2
Frequently Asked Questions
What is the simplest area formula?▾
Area = ½ × base × height. It works for any triangle if you know a base and the perpendicular height to it.
How does the SAS formula work?▾
Given two sides and the included angle, Area = ½ · a · b · sin C. The sine factor accounts for the angle between the sides.
When should I use Heron's formula?▾
When you know all three side lengths but no angles. Compute the semi-perimeter s = (a+b+c)/2, then Area = √[s(s−a)(s−b)(s−c)].
Do these methods give different answers?▾
No — for the same triangle they all give the same area. They're just different algebraic paths to it.