Triangle Calculator
Solve any triangle given 3 sides (SSS) — area, angles, perimeter.
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Formulas
About the Triangle Calculator
Whether you are at a desk or on your phone, the Triangle Calculator makes everyday maths and number work easy — and it is completely free. Solve any triangle given 3 sides (SSS) — area, angles, perimeter.
How it works
Type your numbers into the boxes. The answer shows up right away — you do not have to press a button. If you change a number, the answer changes too. So you can try different numbers and watch what happens, or check an answer you worked out yourself. Just make sure each box has the right kind of number in it.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
How do I use the Triangle Calculator?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Is it free? Does it work without internet?
Yes to both. It is free with no sign-up, and once the page has loaded it keeps working even with no internet.
Where does my data go?
Nowhere — every calculation runs on your own device. Nothing you enter is uploaded, logged, or stored.
Common Use Cases
Get an answer fast
Type what you have and get the answer in seconds — on a phone, tablet, or computer.
Try different numbers
Change one thing and watch the answer change. It is an easy way to compare your choices.
Nothing to set up
Open the page and start. There is nothing to install, and no account to make.
Safe and private
Everything you type stays on your device. Nothing is sent to a server or saved.
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