This area of an oblique triangle calculator computes triangle area from base and height, side-side-side, side-angle-side, or two angles and a side.
Math
Area of an Oblique Triangle Calculator
Calculate the area of an oblique triangle.
Calculator
About this calculator
Formula notes
Area = 0.5 × base × height; Heron's formula for SSS; 0.5ab sin(C) for SAS; 0.5a² sin(B) sin(C) / sin(B+C) for ASA.
Worked examples
- Example: a triangle with sides 3 cm, 4 cm, and 5 cm has area 6 cm².
- A triangle with sides 6 cm, 8 cm, and 10 cm has area 24 cm².
How to use it
- Choose one of the four given-data methods.
- Enter the corresponding sides, angles, or base and height.
- Read the area in the selected square unit.
Frequently asked questions
What is an oblique triangle?
An oblique triangle is any triangle that is not a right triangle, so it lacks a 90° angle.
Which method should I pick?
Use whichever values you already know: base and height, all three sides, two sides and the included angle, or two angles and one side.
Limits and interpretation
- Heron's formula assumes a valid triangle; invalid side lengths are rejected by the calculator.
- Angles are measured in degrees in this tool, so convert radians before entering.