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Triangle Solver — Free Online Calculator

Triangle Solver solves Law of Cosines: c² = a² + b² − 2ab·cos(C) — solves for unknown sides/angles given enough known values — Law of Sines is used when only angles and one side are known. Enter your known values and the calculator solves for the rest instantly. All processing happens client-side in your browser, with nothing sent to a server. Free, unlimited, and no registration needed.

How to use Triangle Solver

1. Enter your known values in the fields.
2. The result updates instantly as you type.
3. Copy or note down the result.

Frequently asked questions

What formula does Triangle Solver use?

Law of Cosines: c² = a² + b² − 2ab·cos(C) — solves for unknown sides/angles given enough known values — Law of Sines is used when only angles and one side are known.

Can I use it on my phone?

Yes. The layout adapts to small screens and behaves the same on mobile as on desktop.

Is my input saved anywhere?

No. Values stay in your browser and are gone as soon as you close the tab.

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