Archimedes' Book of Lemmas - - A collection of all 15 propositions from Archimedes' Book of Lemmas with complete proofs, each accompanied by a Java illustration.
Bob's Pages - - A collection of interactive geometry applets. Topics include polyhedra, Poncelet's porism, Soddy's hexlet, Mandelbrot set, Steiner porism, Pappus's chain, Repulsion polyhedra and stereo pictures.
Center of Points in 2- or Higher-dimensional Space - - It provides important formulations for finding a center of points in 2 or higher dimensional space. It can be used in drawing delauney triagulation and voronoi diagram in two or higher dimensions. It also describes how many points are required in defining a center in n-dimensional space.
The Complete Quadrilateral - - Several properties of the complete quadrilateral illustrated with Java applet.
Erich's Packing Center - - Graphics and links for various packing, tiling and covering problems.
Fundamentals of Geometry - - Free online book on geometry in pdf format. Contains material not easily found elsewhere from detailed exposition of elementary absolute geometry based on Hilbert's axioms to more advanced topics.
Geometry and the Imagination in Minneapolis - - Geometry exercises for a two-week summer workshop led by John Conway, Peter Doyle, Jane Gilman and Bill Thurston at the Geometry Center in Minneapolis, June 1991.
Geometry Center - - Web site for the (now closed) Center for the Computation and Visualization of Geometric Structures at the University of Minnesota. Graphics, multimedia, software, teaching resources.
Geometry Formulas and Facts - - Excerpts from the 30th Edition of the CRC Standard Mathematical Tables and Formulas (1995), namely, the geometry section minus differential geometry.
Geometry from the Land of the Incas - - Presents problems involving circles and triangles, with proofs, SAT practice quizzes and famous quotes. Also, has examples of geometry in Peruvian culture.
Geometry in Action - - Includes collections from various areas in which ideas from discrete and computational geometry meet real world applications.
The Geometry Junkyard - - Usenet clippings, web pointers, lecture notes, research excerpts, papers, abstracts, programs, problems, and other stuff related to discrete and computational geometry.
GLaD Comments - - A new type of geometric construction that was discovered by Dan Litchfield and David Goldenheim. Includes general explanation and sketch examples.
Go Geometry - - Offers a variety of resources for teaching and learning about geometry. Problems and theorems are presented with step-by-step solutions for each proof.
The Kepler Conjecture - - Information on the recent proof of Kepler conjecture on sphere packings.
Math Forum: Geometry POW/POM Search - - Search the Geometry Problem of the Week's archive of creative, non-routine challenges, as well as submissions and commentary, dating back to 1993.
Math Forum: Geometry.research - - Discussion board for geometry professors and instructors to keep informed of the latest research.
Math Forum: Search geometry-forum - - Those interested in examining the previous incarnation of the Math Forum may search the archives of the Geometry Forum.
Morley's Miracle - - A discussion of Morley's famous theorem and the research of which it was a tiny part. 5 proofs are given including J. Conway's, D. Newman's, and A. Connes'.
Sangaku: Reflections on the Phenomenon - - Critical reflections on the sangaku phenomenon accompanied by a collection of solved sangaku problems, many with interactive Java illustrations.
Steiner Surfaces - - Mathematical descriptions and ray-traced images of various types of Steiner surfaces.
Tim Lister's Hyperbolic Geometry - - Cabri constructions for the demonstration of the basic concepts of hyperbolic geometry in the Poincare disc model.
Xah's Personal Page - - Features an illustrated dictionary of special plane curves, a paper on wallpaper groups, mathematics image gallery and links to software packages.
NPR : Mathematicians Get Crafty with Geometry - - A husband and wife from Cornell University have come up with a crafty way to illustrate high-level geometry concepts -- by manipulating yarn into models that help explain the curvature of spaces. The mathemeticians talk with NPR's Jacki Lyden about hyperbolic crocheting. [4:47 streaming audio broadcast] (March 13, 2005)