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Question

as a project in class the students are making aluminum flower pots shaped like cylinders. there is a bottom but n o top. if the pots are 9 inches in hight and have a diameter of 12 incher how many squre inches of aluminum are needed for each pot

Answer 1

We need to calculate the surface area of the cylinder. The formula for the surface area of a closed cylinder (having top and bottom) is S = 2πrh + 2πr². However, for an open cylinder with no top, the formula for the surface area changes to

S = 2πrh + πr².

 

We know that h = 9 in. and d = 12 in. We need r, which is the radius, or 1/2 of the diameter, which is 6 in.

 

So S = 2π(6)(9) + π(6)² = 108π + 36π = 144π in²