Circumference = 2*pi*radius
Diameter = circumference/pi Radius = circumference/2*pi
If you mean the diameter and radius of a circle given the circumference it is:- diameter = circumference/pi radius = circumference/(2*pi)
Circumference = 2 * radius * pi (where pi is approx = 3.14159)So Radius = Circumference / (2 * pi)
To find the circumference of a circle the formula is: 2*pi*radius or diameter*pi
To find the circumfrence you would double the radius and multiply it by pi.
divide 3.14 by circumference and d=2r
Divide the circumference by (2*pi)
Radius = square root of (area/pi) Circumference = 2*pi*radius
circumference = 2 x π x radius ⇒ radius = circumference ÷ (2 x π) Divide the circumference by two times π (≈ 6.283).
If the circumference or diameter is given then you can find the radius or simply measure the distance from the centre of the circle to the circumference.
Divide the circumference by the value of Pi, then halve that result.