Triangle Calculator

Enter any three values (sides and/or angles) with at least one side. The calculator will solve for the remaining three using the Law of Sines and Law of Cosines.

SSS (three sides), SAS (two sides and included angle), ASA (two angles and included side), AAS (two angles and non-included side), and SSA (two sides and non-included angle — the ambiguous case).

When two sides and a non-included angle are given, there may be zero, one, or two possible triangles. The calculator checks for all possibilities and reports the ambiguous case when relevant.

Yes. Select 'Radians' from the unit dropdown. All angle inputs and results will be in radians instead of degrees.

The Law of Sines states that a/sin(A) = b/sin(B) = c/sin(C). This ratio is equal to 2R, where R is the circumradius of the triangle. It is used for ASA, AAS, and SSA cases.

The Law of Cosines generalizes the Pythagorean theorem: c² = a² + b² − 2ab·cos(C). It is used for SSS and SAS cases, and reduces to a² + b² = c² when the angle is 90°.

When all three sides are known, Heron's formula is used: A = √(s(s−a)(s−b)(s−c)), where s is the semi-perimeter.

Heights are perpendicular distances from each vertex to the opposite side. Medians connect each vertex to the midpoint of the opposite side. The inradius is the radius of the inscribed circle, and the circumradius is the radius of the circumscribed circle.

Yes. All calculations run locally in your browser. No data is transmitted, logged, or stored on any server.