"Squares"
Three stacked upon three makes nine
and a larger square.
However, stack three rows of
three rectangles on top of one another
and you get a rectangle, and, since
rectangles are generally despised for their unequal
sides, who needs that? Instead, one
could stack three more
rows of three and get a good solid
square. That, however, would require
asymmetry in method (six upon three) and is thus
unacceptable.
It is impossible to stack any number
of upright triangles and produce any recognizable
shape, much less a square.
The same rings true for pentagons,
octagons, and other impractical shapes.
This must the reason squares are
used to line graph paper.