You make two cylinders using 8.5-11-inch pieces of paper. One has a height of 8.5 inches, and the other has a height of 11 inches. Without c

This net might help you visualise the cylinder

Hi Atoombii        

I think that you are saying that there are 2 peices of paper.

Each one is 8.5 cm and 11cm   and they are each wrapped to make cylinders.

One is 8.5cm high and a circumference of 11cm

and the other is 11 cm high wirh a circumference of 8.5cm

Well, since they both use the same sized peice of paper the surface are of the curved surfaces must be identical.

So if you are refering to the SA of  the open cylinders then they are identical.

If you put ends on your cylinder then the one with the biggest circumference will have the biggest 'end' 

So  the short squat one will have the biggest surface area.