Web Directory

» A Gallery of Interactive On-Line Geometry
   At the Geometry Center.
   http://www.geom.uiuc.edu/apps/gallery.html

» Archimedes' Book of Lemmas
   A collection of all 15 propositions from Archimedes' Book of Lemmas with complete proofs, each accompanied by a Java illustration.
   http://www.cut-the-knot.org/Curriculum/Geometry/BookOfLemmas/index.shtml

» 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.
   http://members.ozemail.com.au/~llan/

» Conjectures Produced by the Program Graffiti
   Graffiti is a computer program that makes conjectures in mathematics and chemistry. Links to the conjectures and bibliography.
   http://cms.dt.uh.edu/faculty/delavinae/research/wowref.htm

» Cuboid and Cube Surface Distances
   A java applet with substantial analysis related to distances on a rectangular box.
   http://www.btinternet.com/~se16/js/cuboid.htm

» Cut the Knot
   Features articles about specific problems, illusions, and puzzles. Includes diagrams.
   http://www.cut-the-knot.org/geometry.shtml

» Encyclopedia of Triangle Centers
   By Clark Kimberling. Over 1000 triangle centres in a searchable compilation with diagrams.
   http://faculty.evansville.edu/ck6/encyclopedia/

» Erich's Packing Center
   Graphics and links for various packing, tiling and covering problems.
   http://www.stetson.edu/~efriedma/packing.html

» 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.
   http://polly.phys.msu.ru/~belyaev/geometry.htm

» GLaD Comments
   A new type of geometric construction that was discovered by Dan Litchfield and David Goldenheim. Includes general explanation and sketch examples.
   http://jwilson.coe.uga.edu/Texts.Folder/GLaD/GLaD.Comments.html

» Geometric Group Theory
   Information and resources about geometric group theory and low-dimensional topology. People, groups, meetings, links.
   http://www.math.ucsb.edu/~jon.mccammond/geogrouptheory/

» Geometry Activities
   By Ephraim Fithian.
   http://homepage.mac.com/efithian/geometry.html

» 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.
   http://www.geom.uiuc.edu/

» 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.
   http://www.geom.uiuc.edu/docs/reference/CRC-formulas/

» Geometry Page from Interactive Mathematics Miscellany
   Includes articles on topics in elementary and not so elementary geometry, many with interactive Java illustrations and multiple proofs.
   http://www.cut-the-knot.com/geometry.html

» 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.
   http://www.geom.uiuc.edu/docs/doyle/mpls/handouts/handouts.html

» 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.
   http://agutie.homestead.com/

» Geometry in Action
   Includes collections from various areas in which ideas from discrete and computational geometry meet real world applications.
   http://www.ics.uci.edu/~eppstein/geom.html

» Geometry/Topology at Michigan State University
   Activities of the geometry/topology group at Michigan State University.
   http://www.math.msu.edu/gt/

» 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.
   http://www.gogeometry.com

» Math Forum: Geometry.research
   Discussion board for geometry professors and instructors to keep informed of the latest research.
   http://mathforum.org/kb/forum.jspa?forumID=130

» Math Forum: Search geometry-forum
   Those interested in examining the previous incarnation of the Math Forum may search the archives of the Geometry Forum.
   http://mathforum.org/kb/forum.jspa?forumID=126

» Mathematical Curves and Surfaces
   Graphical representations of computer generated forms. (French/English).
   http://pagesperso-orange.fr/roger.assouly/

» 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'.
   http://www.cut-the-knot.com/triangle/Morley/index.html

» 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 mathematicians talk with NPR's Jacki Lyden about hyperb
   http://www.npr.org/templates/story/story.php?storyId=4531695

» New Mathematical Findings by Secondary Students
   High school students solve complex geometric problems by using GLad Sketchpad. Page includes diagrams.
   http://www.javeriana.edu.co/universitas_scientiarum/universitas_docs/vol6n2/ART1.htm

» Packomania
   Includes packings of equal objects in containers together with source codes to obtain them numerically.
   http://hydra.nat.uni-magdeburg.de/packing/packing.html

» Paul Bourke's Geometry Page
   Includes formulas, definitions and three dimensional image illustrations.
   http://astronomy.swin.edu.au/~pbourke/geometry/

» Polyedergarten
   Shows paper models of polyhedra.
   http://www.polyedergarten.de/

» Problem of the Minimum Rotation Surface
   Java applet demonstrating the catenary.
   http://home.imm.uran.ru/iagsoft/PMRS_J.html

» Sangaku: Reflections on the Phenomenon
   Critical reflections on the sangaku phenomenon accompanied by a collection of solved sangaku problems, many with interactive Java illustrations.
   http://www.cut-the-knot.org/pythagoras/Sangaku.shtml

» Steiner Surfaces
   Mathematical descriptions and ray-traced images of various types of Steiner surfaces.
   http://www.ipfw.edu/math/Coffman/steinersurface.html

» The Complete Quadrilateral
   Several properties of the complete quadrilateral illustrated with Java applets
   http://www.cut-the-knot.org/ctk/CompleteQuadrilateral.shtml

» The Entropy Reduction Laboratory by Karl-Dietrich Neubert
   Discusses double shell structured periodic systems, platonic spheres, molecular and crystal structures, and FlashSort algorithms.
   http://www.neubert.net/

» The Geometry Junkyard
   Usenet clippings, web pointers, lecture notes, research excerpts, papers, abstracts, programs, problems, and other stuff related to discrete and computational geometry.
   http://www.ics.uci.edu/~eppstein/junkyard/

» The Kepler Conjecture
   Information on the recent proof of Kepler conjecture on sphere packings.
   http://www.math.pitt.edu/~thales/kepler98/

» The Lepidoptera of the Circles
   The Butterfly theorem and its generalizations illustrated by Java applets.
   http://www.cut-the-knot.org/ctk/Lepidoptera.shtml

» Tim Lister's Hyperbolic Geometry
   Cabri constructions for the demonstration of the basic concepts of hyperbolic geometry in the Poincare disc model.
   http://mcs.open.ac.uk/tcl2/nonE/nonE.html

» Wilson Stothers' Inversive Geometry and CabriJava Pages
   Includes Steiner's Porism and the arbelos.
   http://www.maths.gla.ac.uk/~wilson/cabripages/inversive/inversive0.html

» 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.
   http://xahlee.org/PageTwo_dir/more.html