A: So the cover can’t fall into the hole, since the circumference of a circle is the same all around. This isn’t the case for squares or rectangles, which can be angled in a way that the covers could fall into the holes.
Maybe this is common knowledge, but it’s new to me. Wes asked me the question on Tuesday’s piano hunt, and I decided to make this a post just because I learned that while I was in Utah.
I also found a triangle manhole, though. Hm…
