Find the surface area of a cylinder with a diameter of 10 and a height of 45. Use 3.14 for π. Round your answer to the nearest tenth

Question

anonymous · Answer

2(pi)r^2*h

45*2((10/2)pi)^2

anonymous · Answer

ok thanks. but I tried that and I got 22184.1 and that isn't an option. I have tried to do this on my own but I just cant get it.

anonymous · Answer

The solution lies in thinking creatively about what needs to be solved.  The surface area consists of the areas of the top and bottom plus the area of the "side" or "sides".  The top and bottom are equal to each other and each is the area of a circle.  The creative part is the "sides".  Think of the "sides" as a label that you can peel off of a can and that label goes all the way around.  Once you peel it off, it's a rectangle.  The easy dimension is the height. The other dimension is the circumference of the circle.  Think about it.  It goes all the way around the can, so it has dimension of the circumference.  If that's hard to imagine, then just look at a circle on a piece of paper.  When you "unwind" it, it's a line.

So, add up the top, bottom, and the rectangle.

anonymous · Answer

Good luck to you in all of your studies and thx for the recognition! @natykiee 

This explanation is a little different than what you usually get here.  It is intended to get the student involved in the solution instead of just handing over an answer.  Thinking and learning is what it's all about.