Presentation can be downloaded here and viewed below:
Clarification about the property of the sphere (may have been a bit confusing :P) — Of all the regular solids, the sphere is the one that has a maximum volume given a fixed surface area. This means that spherical objects maximize the volume per unit of surface area more than any other shape (i.e. cubes, pyramids, etc.). So those who said that there is a minimum surface area given a fixed volume were actually correct.
Hope this clears things up! Feel free to leave a comment if you’re still confused. Thanks!