The circumference of a cirlce can be found if you know either the diameter (the longest distance from on side on the circle to another) or th radius (half of the diameter).
If you know the radius, multiply it by 2 to find the diameter.
The cricumference = pi x D
This means you times the diameter by pi (3.1415926535...)
The circumference of a cylinder cannot be found. Only the circumference of the two round bottoms can be found. The circumference equals 2pi times the radius.
find the circumference of the circle and multiply it by the height of the cylinder
you divide the surface area by the circumference.
The width times pi equals the circumference.
Diameter * pi (3.14159...) = circumfrerence
Divide the circumference by the value Pi - this will give you the diameter.
Use: 2*pi*radius = circumference
Entire surface area of a cylinder = (2*pi*radius^2)+(circumference*height) If you are given the circumference then radius = circumference/2*pi
C = 2 pi r
Find the radius by dividing the circumference by 2pi then find the area of the base and multiply it by the height
Take the circumference and multiply it by it's height to get the lateral surface area.
C = 2pi * r
You just need to find the circumference of the circular base (or top). It's the same thing. (Hint: use C=pi*diameter to find the circumference).