I threw this together for use with the Mathematics Vision Project's modeling with geometry module: http://www.mathematicsvisionproject.org/uploads/1/1/6/3/11636986/sec3_mod5_modgeo_se_041114.pdf
"c1" and "a1" isolate the right triangles needed to show that the top right rectangle's missing sidelength is b*cos(C) and the top left's is a*cos(C) for showing that those rectangles have the same area. The other rectangles can be done with the same method, but since I am using this during my lecture I felt that for time's sake it was only worth doing one pair. The "lengthies" and "Lines" are just eliminating the framework of the construction to unclog the view. The "Areas" and "Rectangles" are for visualizing all of the rectangles that have the same areas.
