Question

When you look on store shelves, you will see many rectangular prism and cylinder-shaped packages. Why do you think the use of triangular prism, pyramid, and cone-shaped packages is so rare?

Answer 1

Volume to area ratio isn't as good for those other shapes, so it will take more packaging material ($) to hold the same amount of "stuff." Further, practical considerations (can the items be stacked? will they fit easily into a rectangular shelf?) also play a part.