To find the Area of the Cylinder or the coke can you would use the formula A=2πrh+2πr2. R being the radius and H being the height If you plug in the variables 3 for the radius and 8 for the height. You will get 207.35 and you will divide that by your total area. You can make 12(12.90089) cans with the allotted amounted of sheet metal.