posted by Hunter .
The surface area of a cylinder is about 218 in^2. What is the surface area of a smaller cylinder that is smaller by a scale factor of 1/2?
If radius and height are halved, then the total surface area is 1/4 the size. (1/2)^2 = 1/4. So 218 /4 = 54.5 units squared. We get the relationship from SA being 2 dimensions, so we square the ratio. If this were volume, you would cube the scale factor ratio.