https://docs.google.com/presentation/d/17I7wG9AiCSTbdp5bbEw9BTHibVxqkGBUp0azHzY28zY/edit
7.3 Special Right Triangles
7.4 Right Triangle Trigonometry
7.5 Angles of Elevation & Depression
7.6 Law of Sines
7.7 Law of Cosines
http://zukowskimath.blogspot.com/2013/01/77-law-of-cosines.html