Perimeter of a circle 


with π (number pi) approximately equal to 3.14 Radius = AO = OB = r Diameter = AB = 2 r ExampleTake a circle with radius r = 3 cmPerimeter P of the circle = 2 x π x r ≈ 2 x 3.14 x 3 ≈ 18.84 cm² Calculate the perimeter of a circle 