Perimeter Calculator
Compute the perimeter of common shapes (rectangle, square, triangle, circle...).
Input Data
Sides
Preset
Results
Total perimeter.
12
Explanatory note about the result.
3 邊周長 = 3 + 4 + 5 = 12
At a glance:Perimeter = sum of side lengths; for a circle use 2πr. Complements area calculators.
Formula
P = Σ sides; circle P = 2πr.
How to Use
- Pick a shape and enter sides.
- The tool returns the perimeter.
Case Studies
Rectangle 3×4
2(3+4) = 14.
FAQ
Perimeter vs area?
Perimeter is the boundary length; area is the enclosed region.
Related Tools
References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.