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I've been asked to teach "Foundations of Geometry" at the University of South Carolina. Apparently, professors in the past have all done very different things, and I have a lot of choice in the matter. What course would you like to see?

Some constraints:

  • I want to say at least a little something about (1) the axiomatic approach (e.g., Euclid's axioms), (2) the modern approach (cool theorems such as Ceva's theorem, the nine point circle, etc., etc.), (3) the constructive approach, with straightedge and compass.
  • My students differ in background and motivation. Most of them are prospective high school math teachers. Typically they have seen some proofs, but not a lot; for example, they may have proved that the sum of two odd numbers is even. Most of the students won't yet have taken analysis, or algebra, or any other course obliging them to work really hard.
  • It has been a long time since I have seriously dealt with the subject, so I will definitely want a good book (or books) or other materials to follow.
  • I won't say anything about projective or other non-Euclidean geometry, because there's another course for that.

I asked a similar question on MathOverflow, but I was a little bit spooked by the answers. I'm sure that the books of Hartshorne and Hadamard are excellent, but I suspect these might be better for stronger students. (And the Hartshorne book discusses "geometry over fields", etc., and most of my students won't have taken abstract algebra.) Some respondents rolled their own solutions -- but are there really not good source materials out there?

My colleague taught a course out of Isaacs' book -- but he really went the extra mile (more like the extra ten miles). He said that the exercises were a bit too difficult, and that he was constantly having to give the students hints, and he slaved over writing up complete solutions. I believe this would not work as well for me as it would for him: he has a very approachable demeanor that I haven't (yet) been able to duplicate, and I'm afraid the students would be unlikely to come to my office hours no matter how much I encouraged them.

I've also looked at other books -- Coxeter and Greitzer is very cool, but perhaps more naturally suited to hotshot high school kids. Posamentier looks promising, a review copy is on its way. Clark's book seems to be somewhat off the beaten path (where I'm not quite sure I want to follow), but it looks very interesting and I ordered a review copy of that also. Other suggestions, big or small, would be very welcome. Thank you so much! --Frank

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    http://www.gutenberg.org/files/17384/17384-pdf.pdf2012-07-18
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    The above link by dato is to the book _The Foundations of Geometry_ by David Hilbert (_Grundlagen der Geometrie_ 1899, translated 1902 by E. J. Townsend).2012-07-18
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    See http://math.stackexchange.com/questions/107882/geometry-book-recommendation/107889#107889 and http://math.stackexchange.com/questions/34442/book-recommendation-on-plane-euclidean-geometry.2012-07-18
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    Your reference to "axiomatic," "modern," and "constructive" approaches doesn't make sense to me. Euclid's axioms are constructive -- they state that certain things can be constructed. E.g., the 3rd postulate says we can construct with a straightedge. The examples you give of "the modern approach" are examples of theorems, which can be proved from Euclid's axioms. You may find something of interest here: http://www.theassayer.org/cgi-bin/asbrowsesubject.cgi?class=Q#freeclassQAmm When you describe your students' inexperience with proofs -- haven't they all done proofs in high school geometry?2012-07-18
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    @Ben: I intend for the "axiomatic" portion that the students give very, very rigorous proofs, adhering pretty slavishly to the axioms and not appealing to geometric intuition. Later, I want to switch emphasis, and give the kind of proofs which are typical of most other math proofs. Perhaps the difference is not as big as I imagine, but I think it is real. As for high school geometry, I don't know exactly what the students have done (I intend to find out), but I think it is these "two-column proofs", not in prose, and what they have done should be reviewed, supplemented, and extended.2012-07-18
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    For a good few minutes there I was contemplating how out of touch some of the responders at MO must be to recommend Hartshorne for this course. Then I realized they were not referring to his famous Algebraic Geometry text. phew.2012-07-18

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