Question

What is the surface area of this right circular cylinder?

A - 48pi cm^2
B - 108pi cm^2
C - 88pi cm^2
D - 28pi cm^2

Answer 1

A=2πrh+2πr2

is the surface area formula! Do you think you can plug in the correct numbers into this formula?

Answer 2

Idk i've never done this problem before were barely learning it

Answer 3

Okay, well in your picture, you're given your height and your radius so where it says "r" you can plug in a 2 into it..

Answer 4

and where it says "h" you can plug in a 4!

Answer 5

5* Sorry.

Answer 6

What is the (simple) formula for the area of a rectangle of length L and width W?
What does "circumference of a circle" mean?
What is the formula for the circumference of a circle?
How could you apply this info towards answering the question at hand?

Answer 7

A=4πrh+5πr2
like this?

Answer 8

So that gives you:

Surface Area= 2π(2)(5) + 2π(2) squared..

Answer 9

Do you have a calculator to type what I just posted into?

Answer 10

I only have a computer calculator I don't have a complexed one

Answer 11

Try mathway.com and enter what I just gave you into it.. It can tell you what it is. Tell me what you get when you get it. :)

Answer 12

ok

Answer 13

how do you do the pi thing?

Answer 14

Leaving the answer in terms of pi would be perfectly all right, unless all of the answer choices are given as decimal fractions.

Area of the side: 2pi r h.
Area of one end: ?
Area of 2 ends:

Total area=?

Answer 15

There should be an option on mathway where you can press the pi button if I am correct..

Answer 16

ok @xmissalycatx this is what it gave me Simplify the expression.
Exact Form:
24π

Decimal Form:
75.39822368...

Answer 17

make sure you click the one that says "algebra" though..

Answer 18

Therre is no need to go to mathway, UNLESS the answer must be given as a decimal fraction. 24pi is a better answer than the decimal fraction version.

Answer 19

@DD204 You can keep the exact form, you don't need the decimal just so you know..

Answer 20

@mathmale I'm well aware. Sometimes mathway can be a good device to use though.

Answer 21

ok but I don't have a 24pi in my answer choices ???

Answer 22

so what do i do now?

Answer 23

I think you got 24 pi because you put a 4 instead of a 5?

Answer 24

It shouldn't be 24π so I believe you made some kind of error entering in the mathway..

Answer 25

I tryed again and it gave me 20pi^2
:( :(

Answer 26

You entered \[2\pi(2)(5)+2\pi(2)^{2} \] ??

Answer 27

oh i didn't do the squared thing -.- let me try again

Answer 28

Oh now I got 28pi :D :D thx

Answer 29

thats one of the answer choices

Answer 30

Okie dokie! :D Good job! Do you understand how to work it, though?