For surface area you would calculate. Surface area of a sphere. From my experience with these Id say thats about right.
For a cube of size 1.
Well our surface area you have six faces that are each have an area of x squared so our surface areas going to be six x squared. When you divide surface area by volume you get a special ratio called the surface-area-to-volume ratio. From my experience with these Id say thats about right. This is important if you are a cell that depends on diffusion through your cell wall to obtain oxygen water and food and get rid of carbon dioxide and waste materials.