Alright, I'll go back over it next time. I see what you mean, but I haven't really thought that far ahead in my program. I just made the class to really practice it and don't really know what else I can do with the shape. I was thinking of making it either choose between 3-D or 2-D, the leading on to Volume, Density, Surface Area etc. But I feel this may make my program a little messy so I wanted to include each within a class of a seperate file and now that I know it's possible i'll have to have a little play around and post my results. But I see what you mean, like when I call Volume.Sphere or Density.Sphere etc, it could be Sphere.Volume or Sphere.Density.

Thanks again.