•      Trigonometry is a marriage of Geometry and Algebra.  In the 15th century, Jamshīd al-Kāshī provided the first explicit statement of the law of cosines in a form suitable for triangulation. In France, the law of cosines is still referred to as the Théorème d'Al-Kashi. The theorem was popularized in the Western world by François Viète in the 16th century.

Our Trigonometry textbook was written by Paul A. Forrester in the 1970's, and is quite possibly the world's most perfect math textbook.  There is plenty of practice in every chapter and word problems are the last section of each chapter in the book.  There are 6 chapters.  We do chapters 1-3 in the 1st Semester and do chapters 1-6 in the 2nd Semester.

We introduce SohCahToa in chapter 1.  We graph sinusoids, that is functions with sine and cosine, in Chapter 2.  The proofs chapter is chapter 3 where we introduce Trig identities like sin^2x+cos^2x =1.  Chapter 4 is about rotary motion, v = r * w, and graphing inverse functions.  Chapter 5 is where we work with oblique triangles, that is non-right triangles, with the law of sines and cosines.  And we wrap up the year with graphing functions on the polar coordinate plane, where we graph very cool shapes like roses and limacons.   Any leftover time we have at the end of the school year will be devoted to a short unit on Solid Geometry.