PreCalculus - Trigonometry: The Law of Cosines (15 of 15) Heron's Formula Proved

In this video I will prove Heron's Formula.

[Golden_Tortoise]

Wow that is impressive. "We WANT to get to this" then "we WANT to get to this, " etc. to get to the simplest form type of logic takes an impressive amount of knowledge and forward thinking. Really for any proof.

[sarahmanchester]

Very nicely presented - clear & easy to follow! I will definitely share with my geometry students.

[aejahrojas]

this was absolutely amazing! You saved me for my trigonometry project

[yuhema]

AWWW it's such a beautiful derivation! Who first invented this was surely a genius!

[thevibe]

why do you write a^2+b^2-c^2 except (a+b)^2-c^2 at 8:52?

[ptyptypty]

I just figured out HOW Heron aka Hero Of Alexandria discovered this.. it's simple... he did NOT have a Cell phone, a Computer, a Car, a Calculator, he did not have electricity or distractions... he had Lots of time on his hands with little to No That's how he figured it out.. :)...

[ptyptypty]

Okay, Michel.. I came back and rewatched this Video!! AMAZING how clear and concise your presentation style is. Well Done!! My cat watched it with me and she has a question for you: "Meoowww.. mew mew.. Meowww ??" :)

[QuintinMassey]

I was about to ask why (1-cos^2(c)) equal to (1-cos(c))(1+cos(c)), but then realized that:

(1+cos(c))(1-cos(c)) = 1-cos^2(c) by distributing out the left side. Totally thinking out loud :)

[احسانملکی-فث]

Excellent Sir.
Can this formula be proven the same way if our original triangle has an angle of more than90°?

[ahmedbaig]

I will say excellent because its the 5th deminstration to prove the Haroo's farmula. Wht we can nit f7nd the c8s angke.