Man holes. in most cases , are round because it is the easiest shape to put back into place. Very little alignment is necessary to get them set properly.
There is no definition of the word cicle, however the term circle denotes a round shape that is completely uniform. For example, a wheel is a circular shape.
cicle or semi circle
cicle
cicle\
cone
Manholes are round to prevent them from falling back into the hole. They are manufactured with an indention around the edges to allow them to fit flush with the surface. If they were square (or any shape other than round), it would be possible to lift and turn it so that it the cover fell into the hole -- both expensive to replace and very dangerous to anybody down below.
Because they are meant for a man to go through them
There are approximately 100,000 manholes in Manhattan.
Manholes are human access points for when the sewer system needs maintenance or repair.
They can be any shape ! We have square and rectangular ones in my town (and there's at least a couple of triangular ones too !)
East Midlands International CiCLE Classic was created in 2005.
it is a sphere not a cirlce.