How to lie using visual proofs

Three false proofs, and what lessons they teach. New notebooks: https://store.dftba.com/collections/3blue1brown/products/mathematical-quotebook-notebook Help fund future projects: https://www.patreon.com/3blue1brown An equally valuable form of support is to simply share the videos. Here's a nice short video on the false pi = 4 proof https://www.youtube.com/watch?v=6Qnfd5dRyf4 Time stamps: 0:00 - Fake sphere proof 1:39 - Fake pi = 4 proof 5:16 - Fake proof that all triangles are isosceles 9:54 - Sphere "proof" explanation 15:09 - pi = 4 "proof" explanation 16:57 - Triangle "proof" explanation and conclusion Thanks to these viewers for their contributions to translations French: azerty314159 Portuguese: Wagner K. Martins ------------------ These animations are largely made using a custom python library, manim. See the FAQ comments here: https://www.3blue1brown.com/faq#manim https://github.com/3b1b/manim https://github.com/ManimCommunity/manim/ You can find code for specific videos and projects here: https://github.com/3b1b/videos/ Music by Vincent Rubinetti. https://www.vincentrubinetti.com/ Download the music on Bandcamp: https://vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown Stream the music on Spotify: https://open.spotify.com/album/1dVyjwS8FBqXhRunaG5W5u ------------------ 3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted on new videos, subscribe: http://3b1b.co/subscribe Various social media stuffs: Website: https://www.3blue1brown.com Twitter: https://twitter.com/3blue1brown Reddit: https://www.reddit.com/r/3blue1brown Instagram: https://www.instagram.com/3blue1brown Patreon: https://patreon.com/3blue1brown Facebook: https://www.facebook.com/3blue1brown