A tale of two problem solvers | Average cube shadow area

What's the average area of a cube's shadow?
Numberphile video on Bertrand's paradox:    • Bertrand's Paradox (with 3blue1brown) - Nu...  
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There's a small error at 19:30, I say "Divide the total by 1/2", but of course meant to say "Multiply..."

Curious why a sphere's surface area is exactly four times its shadow?
   • But why is a sphere's surface area four ti...  

If you liked this topic you'll also enjoy Mathologer's videos on very interesting cube shadow facts:
Part 1:    • The cube shadow theorem (pt.1): Prince Rup...  
Part 2:    • The cube shadow theorem (pt.2): The best h...  

I first heard this puzzle in a problem-solving seminar at Stanford, but the general result about all convex solids was originally proved by Cauchy.
Mémoire sur la rectification des courbes et la quadrature des surfaces courbes par M. Augustin Cauchy
https://ia600208.us.archive.org/27/it...

The artwork in this video was done by Kurt Bruns

Thanks to these viewers for their contributions to translations
Hebrew: Omer Tuchfeld
Hindi: rajeshwar-pandey

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Timestamps
0:00 - The players
5:22 - How to start
9:12 - Alice's initial thoughts
13:37 - Piecing together the cube
22:11 - Bob's conclusion
29:58 - Alice's conclusion
34:09 - Which is better?
38:59 - Homework

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https://github.com/3b1b/manim
https://github.com/ManimCommunity/manim/

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Music by Vincent Rubinetti.
https://www.vincentrubinetti.com/

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https://open.spotify.com/album/1dVyjw...

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