Circumference of a circle: 2 x pi x radius.
The circumference, C, of a circle is given by the formula
To find the circumference of a circle the formula is: 2*pi*radius or diameter*pi
(pi)D
C=Pi x diameter
diameter = circumference/pi (pi = 3.14159265 or 3.14 for rough approximation).
If you are given the radius of the circle, you can use the formula: diameter = 2*radius If you are given the circumference of the circle, you can use the formula: diameter = circumference/pi
The circumference, C, of a circle is given by the formula
Circumference = (diameter) multiplied by (pi)
Circumference of a circle = (pi) x (diameter)
To find the circumference of a circle the formula is: 2*pi*radius or diameter*pi
(pi)D
C=Pi x diameter
diameter = circumference/pi (pi = 3.14159265 or 3.14 for rough approximation).
It is not clear whether you want the formula of some aspect (area or circumference) of a circle when given its radius or a formula for its radius when given some characteristic measure of the circle.
The perimeter of a circle is its circumference
To find the radius of a circle when given the circumference, you should start with the formula for circumference, which is this: circumference = 2*pi*radius To solve for the radius, you would the have to divide the circumference by 2*pi leaving you with a formula like this: radius = circumference/(2*pi) pi≈3.14159
We've not been given a circle.