About the Triangle Calculator
Enter any three values — including at least one side — and the triangle calculator finds every missing side and angle using the laws of sines and cosines. It also shows area, perimeter, heights, inradius, circumradius and a scaled drawing. Ambiguous SSA cases show both solutions.
How to use it
- Enter at least three values, including at least one side.
- Angles are in degrees.
- Review all solved values and the diagram.
Formula & method
Law of sines: a/sin A = b/sin B = c/sin C
Law of cosines: c² = a² + b² − 2ab·cos C
Heron: Area = √(s(s−a)(s−b)(s−c))Frequently asked questions
Why can SSA give two triangles?
With two sides and a non-included angle, the third side can sometimes swing to two different positions — the “ambiguous case”. The calculator shows both when they exist.
Results are estimates for general information only and are not financial, tax, legal or medical advice. Please confirm important decisions with a qualified professional.