So Just Why *Are* Manhole Covers Round?

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Note: This has nothing to do with a person being a Square.

Circles and Squares were created equal.

Have a happy yellow "smiley face" sticker kind of a day!

I'll ask you next time I need a manhole designed! :)

Because they are manufactured in that way. Next question is "Why factories do that?" I do not know. I don't have a degree in this industry.
So how? :)

You can fit the same size fat guy into a circular hole and a square hole, so why not just save material and make a circle. Ehehe...*picturing a fat guy jumping into manhole*

I just asked someone this question at an interview (I know, I should be shot). The reply was "what's a manhole cover?". Serves me right, huh?

I am posing this question as a mystery for my geometry students to solve. I am not allowing the use of the Ineternet, but I want to give them clues to solving the mystery. Can you tell me how heavy most manhole covers are?

One reason sewer covers are round is that no matter what position it is in, it won't slip through the hole. Circles and squares are not made equally because if you turn a square sewer cover perpendiculer to the ground and diagonally to the hole, and let go, you will hear a clang or possibly a crash as the thing hits the bottom of the sewer.

My manhole doesn't have a cover...

Geoff... Perhaps it should...

The question implies that a manhole cover is round universally and eternally. This could never be proved. The question should not have been asked.

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