Flat Earth Math | Rebuttal to Bev 3.3: Perpendicular to a Circle @FlatEarthMath | Uploaded July 2023 | Updated October 2024, 1 hour ago.
In this video I attempt to draw perpendiculars to a circle, based on first principles (literally starting with the Pythagorean theorem). If you've forgotten the stuff from the first week of Calculus, you might enjoy this!

My "Round 3" rebuttal video, which had the math challenge:
youtube.com/watch?v=i7tlKC5aXlg

Round 3.1 with the answer to the challenge:
youtube.com/watch?v=3sQdSF7USO0

If you want to use the spreadsheet click the link below, then use File menu--Make a Copy to put it into your own Google Drive. If you don't have a Google account, you can still download it as an Excel file and play with it that way.
docs.google.com/spreadsheets/d/19SmhYAXqQbI1OnU-8vaUZCl4McOfp90kvf8h8FMBd0U/edit?usp=sharing

0:00 Intro
2:26 Dunning-Kruger...'tis Globe!
3:54 Deriving formulas
7:06 Testing at 45º
8:51 Quarter-circle with 3 test points
10:28 "Slope Assistant" spreadsheet
11:47 Testing 3 points
15:43 Radius perpendicular to circumference
16:58 Practical application of slope of a curve
19:22 Final Thoughts