Why do you think manholes are round in shape?
(You need to think a little crooked for this )
(In reply to
re: A solution by levik)
An equilateral triangle, or a square, or a pentagon or a hexagon etc. could be turned in such a way that it could be passed through a hole that it covers. It is physically impossible to make the round cover go thru the round hole. For example the diagonal of a square is by definition larger than any given side (or all sides). Knowing this you could easily pass a square cover thru the same sized square hole. For the purpose of this problem the diameter of the circle equates to the diagonal of the square. While the square can be turned to allow it to pass thru the hole, you cannot do this with a circle. I'm not very good at stating these things clearly. I know what I mean but don't know the best way to say it. I would appreciate anyone who might be able to explain it more clearly.
re(2): A solution
