Triangle Calculator
Solve a triangle from SSS, SAS, ASA, AAS, or SSA inputs and calculate sides, angles, area, perimeter, altitudes, medians, and circle radii.
The preview highlights the values to enter. For the ambiguous case, the known angle is opposite one of the known sides.
Enter all sides in the same unit. Angles use degrees, and area is reported in the matching square unit.
Triangle solver for sides and angles
English triangle-calculator intent expects a full triangle solver, not only an area formula. This tool supports SSS, SAS, ASA, AAS, and the ambiguous SSA case, then reports the main derived properties.
The law of cosines connects a side with the included angle and the other two sides.
The law of sines solves angle-side cases and explains the possible two-solution SSA case.
Frequently Asked Questions
Sources and References
- Triangle CalculatorCalculator.net
- Oblique Triangle CalculatorOmni Calculator
- Solution of TrianglesWolfram MathWorld
Calculations are based on the listed reference sources. Links open in a new tab.
Related Tools
Calculate triangle area from base and height, three sides, two sides and an included angle, angles and a side, coordinates, right-triangle legs, or circle radii with three sides.
Calculate triangle perimeter from three sides, one equilateral side, equal side and base, or two right-triangle legs with triangle inequality checks.
Calculate triangle area from three side lengths using Heron's formula, with semiperimeter, triangle inequality checks, heights, angles, and incircle/circumcircle radii.
Calculate right-triangle legs, hypotenuse, acute angles, area, perimeter, altitude to hypotenuse, projections, medians, and circle radii.
Solve triangles with the law of sines for ASA, AAS, and SSA cases, including the ambiguous case when two triangle solutions are possible.
Find the hypotenuse, find a missing leg, or check right-triangle side relationships with the Pythagorean theorem.