curved surface areas?

Question

how do you calculate the curved surface area of a cylinder?
I have been given the radius - 54cm
and the height - 10cm

Answer 1

Imagine a tin can --such as soup come in-- with the top and bottom removed. That's your cylinder, right? Right! Now, cut it from top to bottom perpendicular to the top and bottom with a pair of scissors and flatten it out on a table top. Now you have a rectangle, right? Right! How do you calculate the area of the rectangle? Length (L) times Width (W), right? Right! L x W = Area.

Now, you know the width, it is the height of the cylinder. But what is the length? Well, it was originally a circle before you flattened it out. Oh!! It is the circumference of the circle. (Well, duh!) So, how do you find the circumference of that circle? Right! 2 x pi x R. So, now you can put it all together:

Area = L x W, but L is the height of the cylender, and W is the circumference of the base, so

Area = height x 2 x pi x R

Area = 10 cm x 2 x pi x 54 cm

I'll let you do the arithmetic. Right? Right!

HTH

Charles

Answer 2

A cylinder when opened up yields a rectangle with sides of lengths 2 * pi * r and h. Thus area of this rectangle is the csa.
csa = 2 * pi * r * h
plug in 3.1416 for pi, 54 for r and 10 for height.

Answer 3

Unroll the cylinder!!!!

It becomes a rectangle!!!!

h = 10

w = pi x d = 2 x pi x r = 108 x pi

area = h x w = (1080 x pi) square cm

Answer 4

You now the equation of the circumfrence of a circle which is

C = 2*pi*radius

The surface area of the cylindar is then just the circumfrence of the circular face multiplied by the height

Answer 5

The formula for height of cylinder is:
2 * (pi) * (radius) * (height)

r = 54 cm
h = 10cm

CSA = 2 * 3.14 * 540
= 3391.2 cm^2

Answer 6

if sq. is rotated about an part, the outdoors will be cylinder, whose radius will be 6cm and top will be 6cm. so floor section will be 2*pi*r*h, and entire floor will be 2*pi*r*h+pi*r^2