Geometric dissections on the web

A geometric dissection is a cutting of one or more figures into pieces that can be rearranged to form other figures. Dissections are often cast as puzzles, in which the object is to use as few pieces as possible. These geometrical puzzles fall under the category of mathematical recreations. Some dissections are relatively simple; others are deceptively simple, employing elegant approaches. A number of dissections can be found on the web:

Animations of dissections
- Mathsite's Polygon Dissection Gallery
- Henry Dudeney's dissection of an equilateral triangle to a square, on Robert Fathauer's Hinged Dissections webpage.
- Dudeney's hinging of a triangle to a square, and one
  hinging of a triangle to a hexagram, on Therese Eveilleau's webpages.

Dissections as puzzles
- Haberdasher's Puzzle, on Edward Ball's Academo.org .
- figure on a square grid to a square, on Puzzles.com.
- various figures into rectangles, on Torsten Sillke's webpage.
A variety of dissections
- Gavin Theobald's geometric dissections - What a treasure house!
- Geoffrey Bennett's octagon to square,
  my two unequal hexagrams to one, and
  my five decagons to one, on my book's web page.
- Philippe Chevanne's web pages on dissections.
- 11-square to 2-, 6-, and 9-squares, and
  Harry Lindgren's hexagon to square, and
  hinged dissections of polyominoes, on David Eppstein's Geometry Junkyard
- Photocopies of two papers on dissections, by Henry Perigal.
Paradoxes
- Curry's Paradox, on Torsten Sillke's page on Jigsaw Paradox.
- 8 x 8 square to 5 x 13 rectangle, on David Eppstein's Geometry Junkyard.
- A `proof' that 88 = 89 = 90 = 91, supplied by Noam Elkies.
Ads for commercially sold puzzles
- Paul Busschop's hexagon to a square, and
  Henry Dudeney's pentagon to a square, - Walter Hoppe's hardwood puzzles on John Rausch's PuzzleWorld.

Maintained by Greg Frederickson,
If you know of any dissection pages that I have missed, please send me email.

Last updated October 15, 2018.