Skip to main content

Why are manhole covers round? - Marc Chamberland

647,528 Views

5,655 Questions Answered

TEDEd Animation

Let’s Begin…

Why are most manhole covers round? Sure it makes them easy to roll, and slide into place in any alignment. But there’s another, more compelling reason, involving a peculiar geometric property of circles and other shapes. Marc Chamberland explains curves of constant width and Barbier’s theorem.

About TED-Ed Animations

TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator Marc Chamberland
  • Director Adam Comiskey
  • Artist Clarrisa Hanekon, Ryan Flynn, Calvin Bacon
  • Script Editor Eleanor Nelsen
  • Narrator Addison Anderson

More from Math In Real Life