Why are manholes covers round?
Correct answer: They won't fall into the manhole itself

Birdiemom
Player #48458, that's ridiculous. There are manholes wherever there are drain systems.

Birdiemom
Manhole covers are occasionally dislodged by passing vehicles, and could fall in the hole if they were any shape but round

☆☆LGM---3--21-19
wrong !
marylin vos savant
explained this before in
her newspaper column.