Triangle Calculator

Enter any 3 known values (at least one side) to solve the triangle.

Known Values (any 3, at least one side) Side a Side b Side c Angle A (deg) Angle B (deg) Angle C (deg)

Methods Used

Law of Cosines: relates sides and included angle
Law of Sines: relates sides and opposing angles
Heron's Formula: area from three sides

Tips

Angles must sum to 180°
Triangle inequality must hold (sum of any two sides greater than third)