How to use this tool
Choose the measurements you know, then enter the matching sides and angles.
Side a is opposite angle A, and likewise for b/B and c/C. An SSA case may have two solutions; inspect both.
Cosine rule: a²=b²+c²−2bc cos A; sine rule: a/sin A=b/sin B=c/sin C
Worked example
6 · area (first solution)
Fixed example using the settings below. Monetary examples use USD; dates and times use their stated reference values. This example stays unchanged when you edit your calculation.
Example inputs
- Known measurements: SSS: three sides
- Side a: 3
- Side b: 4
- Side c: 5
Method illustration: Sides 3,4,5 have area 6 and angles about 36.87°,53.13°,90°.
Assumptions and limits
- Side letters are opposite their corresponding angles. SSA can have zero, one or two valid triangles; all valid solutions are reported.
Check or report a result
Check the units, selected calculation and assumptions first. Compare the fixed example above with your inputs to identify what changed.
Report a calculation issue with the page address, hypothetical inputs, result displayed and result expected. Do not include passwords, bank details or other private information.