answered 10/7/2009 How To Find The Circumference In A Circle With A Diameter Of 20 Meters? The formula for circumference of a circle is 2 x pi x r where pi = 22/7 = 3.14 and r = radius of the circle. In this case if d=20, then r = d/2 = 10 thus, circumference of the circle = 2 x pi x r = 2 x 3.14 x 10 = … Read more