Math 550 Fundamental Concepts of Geometry Professor: Dr. Curtis Bennett Office: UH 2724 Phone: 338-5112 Email: cbennett@lmu.edu Office Hours: TR: 1:35- 3:20, W: 10:00-12:00 and by appointment Textbook: Euclidean and Non-Euclidean Geometries Development and History, Marvin Jay Greenberg, W. H. Freeman and Company, 3rd edition. Prerequisites: MATH 248 Tentative Topics: Introduction Euclid’s postulates – The first four postulates, the need for further definitions, the danger of diagrams. Incidence Geometry - Finite Geometries, models, isomorphism of models. Hilbert Axioms: Betweenness – Pasch’s Theorem Congruence – Side Angle Side Axiom, ASA criteria, Trichotomy law, SSS congruence, Euclid’s Fourth Postulate. Continuity Neutral Geometry: Basic axioms of neutral geometry – Euclid’s first four axioms. Neutral triangles – SSS congruence, alternating interior angle theorem, and the triangle inequality, Saccheri-Legendre Theorem. Basic geometric constructions – angle bisector, perpendicular bisector, replication of shapes. Euclidean Plane Geometry: The parallel postulate – Equivalents to the parallel postulate including the alternate interior angle theorem, the angle sum theorem, the mutual perpendicular line theorem. Euclidean triangles and circles – concurrence theorems, exterior angle theorem, AAA similarity theorem, Pythagorean theorem (and its converse), geometric mean theorem. Trigonometric functions – sine, cosine, law of sines, and law of cosines. Euclidean geometric constructions – rational number construction, basic geometric shapes. Non-Euclidean Geometries Spherical geometry – change of axioms, area of triangles, AAA congruence theorem. Hyperbolic geometry – change of axioms, area of triangles, meaning of parallel. Geometric Transformations: Rigid motions – isometries in 2-dimensional space (rotations, reflections, translations). Similarities and inversions – dilations, similarity transformations. Coordinate systems – definitions, proving theorems using coordinate systems. Perimeter, Area, and Volume: Perimeter and circumference – derive perimeter formulas for circles from polygons compare to the method using integration. Area – compute areas of polygonal regions (signed and unsigned) and use to find area of circles. Volumes and surface areas – find volumes of three-dimensional objects, Cavalieri’s principle. Instruction and Technology: In this course, we will be using classroom Socratic lectures roughly 2 days out of 3 and in-class activity/group work the other day. We will use the Lénárt sphere for investigations in spherical geometry and students will construct a model of hyperbolic space for investigations into hyperbolic geometry. Students will also need to familiarize themselves with Geometer’s Sketchpad, which we will use for some activities. Grading: There will be approximately weekly homework assignments, in class assignments that may involve some time spent completing them at home, a midterm and a cumulative final. At the end of the term, students will hand in a portfolio for the class containing all of their assignments, reflective writings (of no more than a page each) and a comparative journal. Grades will be determined according to the following weightings: Homework & in class work Midterm (Thursday, Oct. 13th) Portfolio Participation Final Exam (Tuesday, Dec. 13th: 2-4) 40% 15% 10% 5% 30% 90% of all points will guarantee students an A or A-, 80% will guarantee students a B+, B, or B-, 70% a C+, or C. However, at the end of the term, these percentages may be reduced slightly. Objectives: (1) Students will be able to solve routine and complex problems in geometry drawing form a variety of strategies. (2) Students will be able to clearly communicate arguments in geometry in everyday and mathematical languages both orally and in writing. In particular, they will be able to solve these problems in context and explore their relation with other problems. (3) Students will be able to use technologies (including Geometer’s Sketchpad and the Lénárt Sphere) appropriately to investigate and solve problems involving Euclidean and non-Euclidean geometry and enhance their understanding of these geometries. (4) Students will be able to articulate mathematical ideas orally and in writing using appropriate terminology and technologies. (5) Students will show an understanding of the foundations and proofs of Euclidean geometry. In particular, students will gain an understanding of (6) Students will solve problems in Euclidean and non-Euclidean geometry and present formal and informal proofs of theorems in Euclidean and non-Euclidean geometry both orally and in writing. (7) Students will be able to discuss how geometry relates to other topics in mathematics like linear algebra, complex analysis, and calculus. (8) Students will see varied teaching strategies in geometry and see how they help content be conceived and organized for instruction, fostering conceptual understanding and procedural knowledge. (9) Students will see multiply ways to solve problems in geometry. (10) Students will formulate and test conjectures in Euclidean and non-Euclidean geometry and judge the validity of mathematical arguments.