Perimeter Calculator
Calculate perimeter and circumference of rectangles, squares, triangles, circles, polygons, and more. Free online perimeter calculator.
Perimeter Formulas
Square: P = 4s
Rectangle: P = 2(l + w)
Triangle: P = a + b + c
Circle: C = 2πr = πd
Parallelogram: P = 2(a + b)
Rhombus: P = 4s
Regular Polygon: P = n × s
Trapezoid: P = a + b + c + d
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