How did they figure out the area of a circle is pi times r squared?
0:00 intro
3:10 Archimedes
6:25 Leonardo and Sato Moshun
8:20 RABH
https://en.wikipedia.org/wiki/File:%E4%B9%9D%E7%AB%A0%E7%AE%97%E8%A1%93%E7%B4%B0%E8%8D%89%E5%9C%96%E8%AA%AA.jpg
https://en.wikipedia.org/wiki/William_Jones_(mathematician)#/media/File:Synopsis_Palmariorum_Matheseos_pi.jpg
https://en.wikipedia.org/wiki/Aryabhata#Approximation_of_%CF%80
Archimedes
https://en.wikipedia.org/wiki/Area_of_a_circle#Archimedes's_proof
Leonardo and Sato Moshun
https://en.wikipedia.org/wiki/Area_of_a_circle#Rearrangement_proof
Cut The Knot area of a circle
https://www.cut-the-knot.org/Curriculum/Geometry/AreaOfCircle.shtml
Area of a circle, formula explained (mathematicsonline)
https://www.youtube.com/watch?v=YokKp3pwVFc
Understanding the Formula for Area of a Circle #shorts (mathematicsonline)
https://youtu.be/0RGz_rvXVpk
Rabbi Abraham bar Hiyya Hanasi
https://www.cut-the-knot.org/Curriculum/Geometry/RABH.shtml
Area of a Circle by Rabbi Abraham bar Hiyya Hanasi
https://u.cs.biu.ac.il/~tsaban/Circles.html
David Garber and Boaz Tsaban, A mechanical derivation of the area of the sphere, The American Mathematical Monthly 108 (2001), 10--15.
https://u.cs.biu.ac.il/~tsaban/Pdf/PublishedBackUp/RabhsphereBU.pdf
Wikipedia
https://en.wikipedia.org/wiki/Abraham_bar_Hiyya#mathematicsvideo
https://en.wikipedia.org/wiki/Archimedes#/media/File:Archimedes_Palimpsest.jpg
References
https://en.wikipedia.org/wiki/Proof_that_%CF%80_is_irrational
https://en.wikipedia.org/wiki/Aryabhata#Approximation_of_%CF%80
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