New Proofs of Old Geometry Theorems

Authors

Bill Derrick, University of Montana, Missoula

Document Type

Presentation Abstract

Presentation Date

2-13-2012

Abstract

A November 1996 proof of the Pythagorean theorem a²+b²=c², by Frank Burk in The College Mathematics Journal (page 409) led to my efforts (with Jim Hirstein) to find proofs to other geometry theorems using Burk's method. In this talk, among other results, I will show a new proof of Ptolemy's theorem and inequality. I will also discuss a proof of the Erdős-Mordell inequality (1937) for triangles, and some of our conjectures for convex quadrilaterals and polygons.

Additional Details

Monday, 13 February 2012
3:10 p.m. in Math 103
4:00 p.m. Refreshments in Math Lounge 109

Recommended Citation

Derrick, Bill, "New Proofs of Old Geometry Theorems" (2012). Colloquia of the Department of Mathematical Sciences. 390.
https://scholarworks.umt.edu/mathcolloquia/390