Triangle Area Calculator
Triangle area from base and height.
How it works
Area = base × height ÷ 2
Base and height must be perpendicular. For three sides use Heron’s formula; this tool uses base × height.
FAQ
How to compute area from three sides?
Use Heron’s formula: with semi-perimeter s=(a+b+c)/2, area = √(s(s−a)(s−b)(s−c)).
Worked example
Base 10, height 6: S = 10×6 ÷ 2 = 30.
Sides 3, 4, 5 (Heron): semi-perimeter 6, S = √(6×3×2×1) = 6.
Notes and limitations
Base × height ÷ 2 requires the height perpendicular to that base. With three sides use Heron, provided the triangle inequality holds.