Question

Which of the following is the surface area of the right cylinder below?

Answer 1

(h is the height of the cylinder, r is the radius of the top)

Surface Area = Areas of top and bottom +Area of the side

Surface Area = 2(Area of top) + (perimeter of top)* height

Surface Area = 2(pi r 2) + (2 pi r)* h

Answer 2

That's the formula I'm using, and my answer isn't a choice.

Answer 3

OK LET ME TRY

Answer 4

Okay. :)

Answer 5

What answer did you get?

Answer 6

I keep getting 622.02 like no matter what.

Answer 7

let me redo it again because i dont get that.. hold on

Answer 8

Alrighty.

Answer 9

did u get that for that part

Answer 10

I did.

Answer 11

and this

Answer 12

Yes, I did.

Answer 13

and this?

Answer 14

Now, I did. Haha.

Answer 15

The only answer even close to that is 169

Answer 16

ok then 169.646*2=339.291

Answer 17

the closest is 169 but thats 500 something which is way off

Answer 18

you need to try and ask the person who gave you this, if there is an error

Answer 19

I don't see my teacher until tomorrow, but I'll ask her. Thank you so much for trying though. :)

Answer 20

your welcome. good luck and sorry :/

Answer 21

No, no! Don't be sorry. Haha. :)

Answer 22

waittttt omg i think that 2(pi r 2) is suppose to be 2(pi r^2)

Answer 23

nope that doesnt work....

Answer 24

The area of the cylindrical wall,
\[\large A=Ch\]
\[\large A=(2\pi r)(h) \qquad=\qquad (2\pi\cdot9)(2) \qquad=\qquad 36\pi\]
The area of the round surface on top,\[\large A=\pi r^2 \qquad=\qquad \pi 9^2 \qquad=\qquad 81\pi\]
We have two of these round surfaces,\[\large 2\cdot 81\pi \qquad=\qquad 162\pi\]

So our total area is,\[\large 36\pi+162\pi \qquad=\qquad 198\pi\]

622?
Woops you were multiplying out the Pi lol :)

Answer 25

try this it gives you 622.035 2πr²+h2πr =
2πr(r+h) so try 2πr(r+h)

Answer 26

@zepdrix is right!!!

Answer 27

Silly mistake, hehe.
Happens to all of us XD

Answer 28

i got that formula from http://www.math.com/tables/geometry/surfareas.htm and am not sure where apexwhatt got it from.....

Answer 29

but then i did more research and found the new right formula