When I was in high school, there was a discussion in either a science or math class about why manhole covers were round. One kid just didn't get it. He even mad

When I was in high school, there was a discussion in either a science or math class about why manhole covers were round. One kid just didn't get it. He even made a paper model. I took his model, and then inserted the lid into the hole diagonally. He facepalmed, and fully understood. What I don't understand is this article though. I gave up on it shortly after talking about ingesting raw sewage.