๐ Triangle Calculator
Area6
Perimeter12
Angles (A / B / C)36.9ยฐ / 53.1ยฐ / 90.0ยฐ
Enter the lengths of a triangle's three sides to automatically calculate its area (via Heron's formula), perimeter, and all three interior angles. Useful for checking math homework or for dimension calculations in DIY and design projects.
How to use
- Enter the lengths of the three sides (a, b, c).
- The area, perimeter, and angles are calculated automatically.
- An error is shown if the three sides you entered can't form a valid triangle.
FAQ
How is the area calculated?
It uses Heron's formula, which computes a triangle's area directly from the lengths of its three sides.
What does the "invalid" message mean?
It appears when the three side lengths you entered can't form a triangle (the sum of two sides is less than or equal to the third side). Double-check your side lengths.
What units does this use?
No specific unit is assumed โ the result is shown in the same unit you entered (e.g. enter cm and you'll get an area in cmยฒ and a perimeter in cm).