Sources

Sources used in this book:

"Basic Trigonometric Ratios." http://www.purplemath.com/modules/basirati.htm (accessed 06/17/11).  

Calculus.com, "Angle of Elevation." Last modified 06/27/2006. Accessed June 19, 2012. http://www.calculus.com/konfuciy.asp?tda=dt&t=392&fs=angle of elevation. Embracing Mathematics, Assessment & Technology in High Schools; A Michigan Mathematics & Science Partnership Grant Project

Holt, Rinehart & Winston, "Geology Application." http://my.hrw.com/math06_07/nsmedia/lesson_videos/alg2/player.html?contentSrc=7240/7240.xml (accessed 5/16/2011).

Holt, Rinehart & Winston, "Right Triangles and Trigonometry." http://my.hrw.com/math06_07/nsmedia/homework_help/geo/geo_ch08_02_homeworkhelp.html (accessed 5/16/2011).

Holt, Rinehart & Winston, "Trigonometric Functions." http://my.hrw.com/math06_07/nsmedia/homework_help/alg2/alg2_ch13_01_homeworkhelp.html (accessed 5/16/2011).

Math Interactives, "Exploring Trig Ratios." http://www.learnalberta.ca/content/mejhm/index.html?l=0&id1=ab.math.jr.shap&id2=ab.math.jr.shap.trig&lesson=html/object_interactives/trigonometry/use_it.html (accessed 5/16/2011).

OnlineMathLearning.com, "Angle of Elevation and Depression." Accessed June 19, 2012. http://www.onlinemathlearning.com/angle-of-elevation.html.

"Right Triangle and Applications." http://www.intmath.com/trigonometric-functions/4-right-triangle-applications.php (accessed 06/20/11).

Weber, Keith. "Teaching Trigonometric Functions: Lessons Learned from Research." Mathematics Teacher, September 2008, 144 -150.