Just to have some activity on this blog, in case people think this is dead (assuming they care) and to not be accused of being a squatter (as if someone wants this blog name).
9gag recently had a posting, with someone confused about pizzas being round, their boxes being square and the slices being triangular.
Of course without consulting any historical reasons (and hence running the risk of being very wrong), the suggestion is this: It’s easier to roll dough to round shapes, square boxes are easier to manufacture, store and move around, and the “triangular” slices are the only way to split the pizza fairly equally. And if you cut a circular shape along its diameter it’ not a triangle but actually a “sector”. And just for some additional information, cutting a circle along a chord forms a segment.
