They don't, once, explain to you why you want a smaller rectangle, they just go on an on about "now the rectangle is 33%". I mean, I intuitively get it, shorter pipe less losses (though I still don't understand what the area of the floor has to do with it, length of pipe is all that matters as far as I can see), but if you're pitching a design concept, you need to actually explain it. It wasn't explained at all.