PRO TIP Block youtube.com at the DNS level — Pi-hole, NextDNS or your hosts file — but allow youtube-nocookie.com and i.ytimg.com. These tutorials keep playing; the rabbit hole does not.

Introduction to Radians (Precalculus – Trigonometry 3)

69.2K views on YouTube

Professor Leonard 212 tutorials here

Mathematics

Where Radians come from, how they are related to the arc length of a circle, and why many formulas only work in radian measured angles.
Support: https://www.patreon.com/ProfessorLeonard