How many square feet of paint are needed to paint the outside of a cylindrical shaped gas tank that is resting on the ground? The diameter of the tank is 20 feet and it is 30 feet high (Because the tank is resting on the ground, the bottom will not be painted.)

Question

anonymous · Answer

What is the paint required to paint 1 square feet?

141823 · Answer

It doesn't include the paint

jonnyvonny · Answer

The formula for the surface area of a cylinder=$$SA=2\pi r^2+2\pi rh$$
However, since one of the sides are NOT being painted, we have to remove 1 "2pi*r":$$SA= \pi r^2+2\pi rh$$
They give us the diameter, which is just 2 times the radius; d=20, r=10, and they give us the height; h=30.
So just plug in:$$SA=\pi r^2+2\pi rh \rightarrow SA= \pi (10)^2 +2\pi (10)(30)\rightarrow SA= 100\pi+600\pi \rightarrow SA=700\pi$$

141823 · Answer

So, with that, 700 would be the answer?

jonnyvonny · Answer

700pi

141823 · Answer

okay, thanks so much

jonnyvonny · Answer

yw, feel free to ask more questions if you need :)

141823 · Answer

I do have one more, if you are not too busy

141823 · Answer

Nevermind,

jonnyvonny · Answer

Lol, sorry for the delayed response, I can give you the answer real quick if you want, however, for the next one; no time to elaborate.