A beautiful and elegant mathematical proof to Heron's formula which uses the incircle and excircles of a triangle. This proof is not very well known, however, it is much more intuitive than the mainstream, algebraic proofs.

Thank you to Mr. Siwanowicz for showing me the proof on that fateful day two and a half years ago, and thank you to my friend asianpear for helping me so much with the video.

For more stuff, check out my website: http://kiraprograms.com

0:00 Introduction
1:07 Find lengths from the incircle
3:14 Find lengths from the excircle
4:11 Use similar triangles to solve for the inradius
7:13 Use the inradius for the area
8:20 Summary and conclusion