Here are resources used on this website and places to delve further into the magic of the nine point circle and it's applications!
Websites:
Books:
- Dwiggins. "Inscribed Quadrilateral Conjecture." Conjectures in Geometry: Inscribed Quadrilateral. University of Minnesota, 12 Feb. 1999. Web. 07 Dec. 2013. <http://www.geom.uiuc.edu/~dwiggins/conj47.html>.
- Ikleyn(4). "Lesson Altitudes of a Triangle Are Concurrent." Lesson Altitudes of a Triangle Are Concurrent. Algebra.com, n.d. Web. 07 Dec. 2013. <http://www.algebra.com/algebra/homework/Triangles/Altitudes-of-a-triangle-are-concurrent.lesson>.
- Ikleyn(4). "Lesson Perpendicular Bisectors of a Triangle Sides Are Concurrent." Lesson Perpendicular Bisectors of a Triangle Sides Are Concurrent. Algebra.com, n.d. Web. 07 Dec. 2013. <http://www.algebra.com/algebra/homework/Triangles/Perpendicular-bisectors-of-a-triangle-sides-are-concurrent.lesson>.
- Khan, Sal. "Unique Circle Through Three Points". Khan Academy. 13 Oct 2011. Web. 7 Dec. 2013. <http://www.khanacademy.org/math/geometry/triangle-properties/perpendicular_bisectors/v/three-points-defining-a-circle>
- Mitra, David. "A Line Which Bisects Two Sides of a Triangle Is Parallel to the Third."Geometry. Math Stock Exchange, 2 Feb. 2012. Web. 07 Dec. 2013. <http://math.stackexchange.com/questions/105084/a-line-which-bisects-two-sides-of-a-triangle-is-parallel-to-the-third>.
- "Thales' Theorem." Wikipedia. Wikimedia Foundation, 12 June 2013. Web. 07 Dec. 2013. <http://en.wikipedia.org/wiki/Thales'_theorem>.
- Weisstein, Eric W. "Nine-Point Circle." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/Nine-PointCircle.html
- Wilson, Jim. “Taking Some Mystery out of the Nine Point Circle with GSP.” Mathematics Education. University of Georgia. Web. 30 October 2013. http://jwilson.coe.uga.edu/Texts.Folder /NinePtCir/NPC.html.
- Chapter 4. Feuerbach's Theorem." University College Cork: School of Mathematical Sciences, 2013. Web. 07 Dec. 2013. <http://euclid.ucc.ie/pages/MATHENR/MathEnrichment/4.Feuerbach.pdf>.
Books:
- Altshiller-Court, N. College Geometry: A Second Course in Plane Geometry for Colleges and Normal Schools, 2nd ed., rev. enl.New York: Barnes and Noble, pp. 93-97, 1952
- Baker, H. F. Appendix to Ch. 12 in An Introduction to Plane Geometry. Cambridge, England: Cambridge University Press, 1943
- Dorrie, H. "The Feuerbach Circle." \S28 in 100 Great Problems of Elementary Mathematics: Their History and Solutions. New York: Dover, pp. 142-144, 1965
- Pedoe, D. Circles: A Mathematical View, rev. ed. Washington, DC: Math. Assoc. Amer., pp. 1-4, 1995
- Wells, D. The Penguin Dictionary of Curious and Interesting Geometry. Middlesex, England: Penguin Books, pp. 76-77, 1991