posted by jeng on .
An aluminum cylindrical juice can has a height of 4 in. and a radius of 6 in. How many square
inches of aluminum are needed to make the can?
Visualize a can, cut off the circles at the top and bottom, and cut open the remaining "sleeve".
Don't you now have 1 rectangle and 2 equal circles?
Find the areas of each and add them up
(hint: the length of the rectangle is the circumference of the circle)