Example: Side a: 5 · Side b: 6 · Side c: 7 → Area (Heron’s formula): 14.6969.
Perimeter: 18
Angles: 44.4° / 57.1° / 78.5°
Frequently asked questions
How do I calculate triangle? Enter your numbers above and the result updates instantly. For example: Side a: 5 · Side b: 6 · Side c: 7 → Area (Heron’s formula): 14.6969.
Is this Triangle Calculator free? Yes — completely free with no sign-up or paywall. It runs entirely in your browser and keeps working offline; the numbers you enter never leave your device.
How accurate is it? It uses the standard published formula for triangle. Results are estimates for planning — not financial, tax, medical, engineering, or legal advice.