clearly, the lateral area is 5*12 = 60 in^2 in both cases
so how to get a different area? The top and bottom must be circles of different sizes
There are only two ways to curl up the sheet into a cylinder. What are they?
And recall that the area of a circle with circumference C is
A = C^2/(4π)
Gandalf took a piece of paper 5'' by 12'' and made a cylindrical can with it. He then put a top and bottom on the can and computed the can's surface area. Frodo did the same with another piece of 5'' by 12'' paper getting a different solution. Compute the surface area of both cans.
2 answers
A = 2(pi*r^2) + pi*2r*h
A1 = 2(3.14*2.5^2) + 3.14*5*12 = 228 in^2.
A2 = 2(3.14*6^2) + 3.14*12*5 = 415 in^2.
A1 = 2(3.14*2.5^2) + 3.14*5*12 = 228 in^2.
A2 = 2(3.14*6^2) + 3.14*12*5 = 415 in^2.
1 answer