diameter of a circle = 2*radius or circumference/pi
to find the circumference of a circle, which is the distance in the outside of the circle you need to use the following formula: C=dx 3.14 or circumference equals diameter times pi. The diamater is the length of the circle from end to end. Not very difficult.
To find the area of the circle pi*radius*squared and subtract the area of the figure inside
The circumference of a circle is the distance arround the edge of the circle. The area of a circle is how big the inside of the circle is.
area of a circle = pi*r2
approximately 28.26 cm2
113.1 square cm
Area = pi*92 = 254.469 square cm to 3 dp
Area = pi*22 = 12.566 square cm to 3 d.p.
A circumference of 78.54m
The circumference of a circle is the perimeter of the circle for a given diamater.
3.142
circumference = pi*4.6
Area of circle: pi*20 squared = 1256.637 square feet to 3 decimal places
The circumference of a circle with a 60-foot diameter is about 118.5 feet.
Divide by pi to get the diameter. Divide the diamater by 2 to get the radius. Pi times radius squared.
You double the radius.. if the radius is 10 the diameter is 20.