Why is it better to have round manhole covers than square ones?
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. Note: A visitor added that manhole covers are round so it is easy for one person to manage; i.e., they can roll it instead of carrying it, and whichever way you put it on is correct. And another visitor added that the manhole covers should be round for the simple reason that the manholes themselves are round!
