Tetrahedral carton of milk Though very frequently formed similar to a cuboid, It isn't unheard of to search out cartons missing suitable angles and straight edges, as in squrounds useful for ice cream. An average alteration for an extension to an existing roofing method is to add a lose roof https://www.tumblr.com/sustainablemilkcartons/785842570013130753/innovating-sustainability-with-eco-friendly?source=share