It is: 2*pi*radius or pi*diameter
Circumference of a circle = 2*pi*radius or pi*diameter
circumference = 2*pi*radius or pi*diameter
Radius and diameter are used for round things. Not particularly useful for describing a net.
to find the diameter of a circle when you only have the circomference you: divide the circomference by pi (approx. 3.14)
the answer is 21. the circomference is 3 times the diameter. so 7 times 3 = 21
Radius = Diameter/2 Diameter = 2* Radius
to get the diameter from the radius you simply multiply the radius by 2 since the radius is half the diameter. d=2r where d = diameter and r = radius
A radius is one half of a diameter so divide by two to get from a diameter to a radius. Or you can multiply the radius by 2 to get to the diameter.
radius = diameter/2