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Triangle Calculator

Solve any triangle — enter three known values (sides and/or angles) and calculate all remaining sides, angles, area, and perimeter.

Three sides known

ABCa=3b=4c=5

Results

Scalene Right

Side a

3

Angle A

36.870°

Side b

4

Angle B

53.130°

Side c

5

Angle C

90.000°

Area

6 units²

Perimeter

12.000 units

  • 100% free — no account needed
  • Runs in your browser
  • Nothing is uploaded

Frequently asked questions

Is Triangle Calculator really free?

Yes. Triangle Calculator is completely free on PureBrowser — every feature, with no account, no trial, and no credit card.

Does Triangle Calculator upload my data?

No. Triangle Calculator runs entirely inside your browser, so anything you type, paste, or open stays on your own device.

Do I need to sign up or install anything?

Neither. There is no account and nothing to download — open the page and Triangle Calculator is ready to use on desktop or mobile.

Does Triangle Calculator work offline?

Once the page has loaded, yes. All of the processing happens locally in your browser, so it keeps working without a connection.