Triangle Calculator

Solve any triangle by SSS, SAS, ASA, or AAS — find all sides, angles, area, and perimeter.

How to Use the Triangle Calculator

Select the known information (SSS, SAS, ASA, or AAS), enter the values, and the calculator solves for all remaining sides, angles, area, and perimeter.

Formula

Uses the Law of Cosines (c² = a² + b² − 2ab·cos(C)) and Law of Sines (a/sin(A) = b/sin(B) = c/sin(C)) to solve triangles.

Frequently Asked Questions

What is SSS, SAS, ASA, AAS?

These are triangle congruence cases: Side-Side-Side, Side-Angle-Side, Angle-Side-Angle, and Angle-Angle-Side. Each uniquely determines a triangle.