>o> Why are manhole covers round and not square? > > The answer is: geometry.
That's the wrong answer. Manhole covers are round because manholes are round. > A circle can't fall through its own hole. > For any polygon, there will be "diameters" > of various lengths. This would allow you > to turn the polygon so that it could fit > through the "diameter" of it's hole. However, there are other shapes with constant diameters (so they won't fit through their own holes in any direction). Those shapes have the added advantage that they don't roll as well as circles. Seth _______________________________________________ etree.org etree mailing list <[EMAIL PROTECTED]> http://mail.etree.org/mailman/listinfo/etree Need help? Ask <[EMAIL PROTECTED]>
