Area of Oblique Triangles

I am pretty proud of myself for this because I modeled it after the Law of Sines and Law of Cosines lessons found on Illuminations. I have to admit, it pretty much all came from my Blitzer Algebra and Trig textbook but I'm still happy that I put it together and am kept lessons consistent throughout the unit.

So here is the 'investigation' where students develop the area formulas:



And next the INB pages we put in our notebooks, inspired by Jennifer Cook's foldable:



Here's what it looks like in real life:

And last but not least, here is the matching powerpoint:



Anybody have an interesting way to introduce or develop Heron's formula?