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
To find the circumference of a circle the formula is: 2*pi*radius or diameter*pi
Circumference of a circle: 2 x pi x radius.
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
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.
Use this formula where r is the radius: C = 2Pi(r)
The circumference is 25.1
Given the circumference of a circle the radius is: r = C / 2xPI So the radius of your circle is 326.7451 ft
c=TT R Given the area, the radius = square root (area / Pi). Given the circumference, the radius = circumf/ 2Pi.
Circumference of a circle is given by 2 X pi X radius of the circle. pi = 3.14 or 22/7.
the Circumference is pi times 2 times radius If you know circumference then you can find the radius. once you know the radius just multiply by 2 to find the diameter.
circumference of a circle = 2*pi*radius or pi*diameter