Question

how do you calculate a cylinders area

Answer 1

it is just base area*height

Answer 2

that is the surface area

Answer 3

it is \[2(\Pi)(r)^2+2(\Pi)(r)(h)\]

Answer 4

"Ok so if the only thing that they give me is 8 and 11 it would be 3.14x8x11?"

what is 8 and 11 @nathalie.springhoff ?

Answer 5

Two circles plus a rectangle.

Answer 6

@Bhagyashree is incorrect.

The area of cylinder is (pi)(r^2)h
surface are is 2(pi)r^2 + 2(pi)rh

Answer 7

area is the same as the surface area @CliffSedge and I looked it up too and I know for sure that the surface area is what you need to calculate if you are asked to calculate the area of a 3-Dimentional shape.

Answer 8

Yes, what's your point? @Bhagyashree

Answer 9

my point is that the formula of area you gave is wrong
"The area of cylinder is (pi)(r^2)h"
surface area is the same as area.
that's all.

Answer 10

πr^2h is *volume* of cylinder, not area. You are incorrect.

Answer 11

This quote, "The area of cylinder is (pi)(r^2)h" was said by ChmE, not myself. I'm assuming he meant 'volume' instead of area, because he also gave the correct formula for surface area immediately below it.
I also gave the same, correct formula for surface area.

"my point is that the formula of area you gave is wrong" - this statement is false, @Bhagyashree

Answer 12

oh i apologise.
i read it wrong. i am really sorry about that @CliffSedge.

Answer 13

lets consider a disk of thickness dx at a dist x from top

now,perimeter of disk dP= 2pi r dx
note that sum of all such perimeters gives the CSA of the cylinder.
integrating both sides, limit of RHS = 0 to h, we get

CSA = 2pir h

which is what we required..

i just did this one for one since i was getting bored ! :P