From Mathologer. Today’s video is about Heron’s famous formula and Brahmagupta’s and Bretschneider’s extensions of this formula and what these formulas have to do with that curious identity 1+2+3=1x2x3. 00:00 Intro 01:01 1+2+3=1x2x3 in action 02:11 Equilateral triangle 02:30 Golden triangle 03:09 Chapter 1: Heron 06:18 Heron’s formula 08:50 Brahmagupta’s formula 10:20 Bretschneider’s formula 11:52…