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Why are manhole covers round? - Marc Chamberland

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TEDEd Animation

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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

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