📐 Geometry & Measurement
Perimeter Calculator
Calculate the perimeter of various 2D shapes using different formulas.
🔷 Shape Selection
Square: P = 4a
📐 Dimensions
Side (a)
cm
🔢 Unit Selection
Unit
Unit: cm
P 0
Perimeter
0 cm
total distance around
Shape Square
Dimensions
Formula Used P = 4a
Area 0 cm²

📊 Perimeter Details

Parameter Value Unit

How the formula works

Square: P = 4a  |  Rectangle: P = 2(l + w)  |  Triangle: P = a + b + c  |  Circle: P = 2πr
  • Square = 4 × side
  • Rectangle = 2 × (length + width)
  • Triangle = side1 + side2 + side3
  • Circle = 2 × π × radius (circumference)
  • Trapezoid = a + b + c + d
  • Parallelogram = 2 × (a + b)
  • Rhombus = 4 × side
  • Ellipse ≈ 2π × √((a² + b²)/2) (Ramanujan approximation)
  • Pentagon = 5 × side
  • Hexagon = 6 × side