Enter dimensions
Fill in any three values (at least one side). The rest are solved for you: SSS, SAS, ASA, AAS and SSA.
Results
Enter your dimensions above and the results appear here.
About the Triangle Solver
The triangle solver is a free online tool: solve any triangle from SSS, SAS, ASA, AAS or SSA. Enter side a, side b, side c, angle a, angle b and angle c and the results update instantly, alongside a labelled diagram so you always know which measurement goes where.
It runs entirely in your browser, so nothing you type is uploaded or stored. Use the share button to copy a link that restores your exact inputs.
Triangle Solver example
Side a = 7 cm
Side b = 9 cm
Angle B = 40°Area = 29.5996 cm²
Perimeter = 29.1568 cm
Side a = 7 cm
Side b = 9 cm
Side c = 13.1568 cm
Angle A = 29.9964 °How to use the Triangle Solver
- Pick the unit your measurements use. All dimensions must share the same unit.
- Enter side a, side b, side c, angle a, angle b and angle c. Focus a field to highlight the matching label on the diagram.
- Read the results as you type. The largest card is the main answer; the others are the related measurements.
- Copy a single value, copy everything, or share a link that keeps your inputs.
Triangle Solver FAQ
What formulas does the triangle solver use?
Law of sines: a/sin A = b/sin B = c/sin C; Law of cosines: c² = a² + b² − 2ab·cos C; A + B + C = 180°.
What does the ambiguous SSA case mean?
With two sides and a non-included angle, there can be zero, one or two valid triangles. When two exist, both solutions are listed.
Which combinations can the solver handle?
Any three known values that include at least one side: SSS, SAS, ASA, AAS and SSA.
Can I use different units?
Yes. Pick the input unit and, if you like, a different output unit. Area results are shown in squared units and volumes in cubed units.
Is this triangle solver free and private?
Yes. It is free with no sign-up, and calculations happen on your device, so your numbers are never sent to a server.
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