Triangle Calculator
Fill any three fields (sides or angles); law of cosines/sines solves everything else including Heron's area.
Enter the required values above to see your result.
How the Triangle Calculator works
The calculation follows the standard method used across the US — no shortcuts, no hidden assumptions. Here is exactly what happens behind the scenes:
Formula
c² = a² + b² − 2ab·cos(C); Area = √(s(s−a)(s−b)(s−c))
Frequently Asked Questions
Which combinations work?
SSS, SAS, ASA, and AAS solve directly. SSA can have two valid answers — check whether both make geometric sense for your problem.
Angles in degrees?
Yes, degrees throughout; results likewise.
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