To calculate the area of a circle use this formula: pi x r2.
Divide your answers by 2Then divide by 3.14Then multiply your answer by 2
1. Multiply pi (3.14) by the radius of the circle (half of the diameter which is the length of the circle on the widest part). 2. Square your result. This uses the formula: Area=πr2where π=3.14
Circumference of a circle = 2*pi*radius or pi*diameter
Double the Radius to Calculate the Diameter.