Manhole Covers

Why is it better to have round manhole covers than square ones?

Answer

This is logical rather than lateral, but it is a good puzzle which can be solved by lateral thinking techniques. It is supposedly used by a very well-known software company as an interview question for prospective employees. Solution A square manhole cover can be turned and dropped down the diagonal of the manhole. A round manhole cannot be dropped down the manhole. So for safety and practicality, all manhole covers should be round. Another answer is also that they can be rolled around to save lifting them..... Another answer especially valuable for heavy covers: it fits in any position and does not need adjustment while the square might need adjustment for up to 45 degees in one or the other direction...