[DannyTN]

#2) Why are manhole covers round?

• because manholes are round.

Design an evacuation plan for San Francisco

• Don't you mean quarantine plan instead?

[shotgun]

They professor asked this question on the first day of my first Intro to Engineering class.

The answer is so they can’t fall into the manhole when your taking them off/on. A square manhole cover could fall in easily because of the diagonal length across the opening of the manhole (hypotenuse)is wider than the width of the sides of the square.