Chronology of Updates
Note
I have placed chronology of updates for 1996 , 1997 , 1998 , 1999 , 2000 , 2001 , 2002 , 2003 and 2004 into separate files. Starting with 1997, the most recent entries appear topmost. Besides providing an insight of this site's evolution, chronology updates may be used for word searches.
December 31, 2005
Pascal in a Cyclic Quadrilateral December 30, 2005
Orthologic Triangles in a Quadrilateral December 29, 2005
All Triangles Are Isosceles December 28, 2005
Pedal Triangle and Isogonal Conjugacy December 26, 2005
Complex Numbers: A Dynamic Tool December 25, 2005
Carpets in a Parallelogram December 24, 2005
Two Rectangles in a Rectangle December 24, 2005
More Bottles in a Wine Rack December 23, 2005
A Property of Rhombi December 23, 2005
Circle-Stacking Theorem December 22, 2005
Gergonne and Medial Triangles Are Orthologic December 21, 2005
Cartesian Coordinate System December 18, 2005
Common Tangents to Two Circles II December 17, 2005
Bottles in a Wine Rack December 16, 2005
Isosceles on the Sides of a Triangle December 15, 2005
Self-descriptive Strings December 14, 2005
3-Term Arithmetic Progression December 12, 2005
Variations on the Theme of Tremas II December 10, 2005
Listing All Permutations: Johnson-Trotter Method December 9, 2005
Dominoes on a Chessboard December 7, 2005
Party Acquaintances December 5, 2005
Common Tangents to Two Circles I November 27, 2005
Straight Tromino on a Chessboard November 22, 2005
Eight Digits Puzzle November 20, 2005
Square From Nowhere November 18, 2005
Parallel Chords November 17, 2005
Variations on the Theme of Tremas November 15, 2005
Counting Triangles II November 14, 2005
Carpet With a Hole November 13, 2005
Carpets Theorem With Parallelograms November 12, 2005
Six Incircles in an Equilateral Triangle November 11, 2005
Equidecomposition of Two Rectangles November 10, 2005
Perigal's Proof of the Pythagorean Proposition November 4, 2005
Equidecomposition of Two Parallelograms November 3, 2005
100 Prisoners and a Light Bulb by Stuart AndersonNovember 3, 2005
The Carpets Theorem November 2, 2005
Wallace-Bolyai-Gerwien Theorem November 1, 2005
Equidecomposition of a Rectangle and a Square October 31, 2005
Equidecomposition of a Triangle and a Rectangle October 31, 2005
The Chaos Game: Address Space vs IFS October 30, 2005
Sierpinski Gasket By Common Trema Removal October 29, 2005
Inequality (1 + 1-3 )(1 + 2-3 )(1 + 3-3 )...(1 + n-3 ) < 3 October 28, 2005
A Property of Equiangular Polygons October 27, 2005
Sierpinski Gasket Via Chaos Game October 15, 2005
Who Needs Monty? October 10, 2005
Upgraded the Y Can't End in a Draw page October 5, 2005
The Lepidoptera of the Quadrilateral October 4, 2005
Y Can't End in a Draw September 28, 2005
Haruki's Theorem September 27, 2005
Fixed Point of Circles Orthogonal to the Given One September 26, 2005
Mirror property of the altitudes September 25, 2005
Hiroshi Haruki's Lemma September 22, 2005
The Two Men of Tibet September 19, 2005
Mathematicians Doze Off September 19, 2005
The Affirmative Action Problem September 18, 2005
A Circle With Two Centers September 16, 2005
Two Perpendiculars From a Point to a Line September 16, 2005
Desargues in the Bride's Chair (with Pythagoras) September 15, 2005
Dividing a Segment by Paper Folding September 15, 2005
Integers and Rectangles: Two Simple Proofs September 14, 2005
Three Tangents, Three Secants September 13, 2005
Area of Median Triangle September 12, 2005
Solitaire in Two Colors September 10, 2005
Loop or Halt September 9, 2005
A Maimed Cake September 8, 2005
Euclid I.43 September 7, 2005
Fractions on a Binary Tree II September 4, 2005
Archimedes' Quadruplets August 17, 2005
The Symmedians August 15, 2005
Bisectal Circle August 11, 2005
Three Tangent Circles August 10, 2005
Ceva and Menelaus Meet on the Roads August 9, 2005
Fermat's Point August 3, 2005
Malfatti's Problem, Hart's Solution July 29, 2005
Properties of the Circle of Similitude July 27, 2005
Circle of Similitude July 26, 2005
Malfatti's Problem July 25, 2005
Internal Tangents to Three Circles July 24, 2005
Inscriptible and Exscriptible Quadrilaterals July 22, 2005
Four Pegs That Form a Square July 20, 2005
A solution to the four travelers problemJuly 16, 2005
Two Colors in Two Rows II July 16, 2005
Two Colors in Two Rows July 15, 2005
Inequality 1/2·3/4·5/6· ... ·99/100 < 1/10 July 14, 2005
Life-like Automaton With Definable Rules July 14, 2005
The Game of Life July 13, 2005
On Bottema's Shoulders II July 12, 2005
On Bottema's Shoulders July 10, 2005
Simple Cellular Automaton July 9, 2005
Weighing 12 coins July 8, 2005
Integer Rectangle on a Chessboard by N. BowlerJuly 7, 2005
Pole and Polar with respect to a Triangle July 6, 2005
Pythagorean Theorem By Plane Tessellation July 5, 2005
Three Tangents II July 4, 2005
See-Saw Lemma July 3, 2005
Birds on a Wire by S. AndersonJuly 2, 2005
Concurrency in the Intouch Triangle July 1, 2005
Dissection of a Rectangle into Two Chessboards June 25, 2005
Proof #54 of the Pythagorean theorem June 24, 2005
A Neglected Pythagorean-Like Formula June 19, 2005
Minimax Theorem June 18, 2005
A Versatile Theorem June 14, 2005
Cube Counting Ambiguity June 12, 2005
Shifting Cube Illusion June 11, 2005
Viviani's theorem II June 10, 2005
Integers and Rectangles: a Proof by Induction June 8, 2005
Integers and Rectangles June 7, 2005
Proof #51 of the Pythagorean theorem June 5, 2005
Hart's Inversor June 2, 2005
Hart Circle June 1, 2005
Polar Circle June 1, 2005
Four Triangles, One Circle May 30, 2005
Feuerbach's Theorem: A Proof May 29, 2005
Incidence in Feuerbach's Theorem May 28, 2005
Rectangle on a Chessboard May 26, 2005
Proofs #49 and #50 of the Pythagorean theorem May 25, 2005
Proofs #46 , #47 and #48 of the Pythagorean theorem May 24, 2005
3-Colors Tower of Hanoi May 23, 2005
Hanoing May 22, 2005
Shepard's Parallelogram Illusion May 21, 2005
Parallelogram Illusion May 20, 2005
Plane Isometries May 19, 2005
Simple Quadrilaterals Tessellate the Plane May 18, 2005
Glide Reflection May 17, 2005
Rotation Transform May 16, 2005
Homothety May 15, 2005
Nagel Line May 12, 2005
Coaxal Circles Theorem May 11, 2005
Apollonian Circles Theorem May 8, 2005
Hex Can't End in a Draw May 5, 2005
Another Pair of Twins in an Arbelos May 5, 2005
Divide a Circle into N Parts of Equal Area May 4, 2005
Lost Boarding Pass May 3, 2005
Area of Arbelos May 3, 2005
Light Bulbs in a Circle May 1, 2005
Translation Transform April 30, 2005
Reflection In Line April 29, 2005
Secant Angles April 27, 2005
Sieve of Squares April 26, 2005
Sieve of Eratosthenes April 22, 2005
Nagel Point of Medial Triangle April 21, 2005
An Interesting Number April 21, 2005
Locus of Points in a Given Ratio to Two Points April 20, 2005
External Angle Bisector April 20, 2005
Tangency Point of Two Circles April 19, 2005
Property of Angle Bisectors II April 19, 2005
Property of Angle Bisectors April 18, 2005
Adams' Circle April 17, 2005
Inscribed Angles April 16, 2005
Inscribed and Central Angles in a Circle April 15, 2005
Divisibility by 7, 11, and 13 April 14, 2005
Inflection Points of Fourth Degree Polynomials April 12, 2005
Munching on Circles April 10, 2005
Signs in a Matrix April 8, 2005
Partitioning 3-Space with Circles April 7, 2005
Maximum Volume of a Cut Off Box April 2, 2005
A Sticky Problem March 30, 2005
Angle Trisection by Hippocrates March 30, 2005
Rotating Gears March 30, 2005
Morphing March 29, 2005
Concurrency in Arbelos March 28, 2005
Structural Constellation March 27, 2005
Archimedes' Twin Circles and a Brother March 26, 2005
Concyclic Points in Arbelos March 21, 2005
Problem of Equal Steps II March 20, 2005
Problem of Equal Steps March 19, 2005
Gothic Arc March 18, 2005
Book of Lemmas: Proposition 15 March 17, 2005
Book of Lemmas: Proposition 13 March 17, 2005
Book of Lemmas: Proposition 12 March 16, 2005
Book of Lemmas: Proposition 10 March 16, 2005
Two Butterflies Theorem III March 15, 2005
Two Butterflies Theorem II March 15, 2005
Book of Lemmas: Proposition 6 March 14, 2005
Book of Lemmas: Proposition 5 March 13, 2005
Book of Lemmas: Proposition 3 March 13, 2005
Book of Lemmas: Proposition 2 March 12, 2005
Book of Lemmas: Proposition 1 March 11, 2005
Rectangle in Arbelos March 9, 2005
4×4×4 Tic Tac Toe March 7, 2005
What Is Arithmetic? March 5, 2005
Hummer's Mind Reader March 3, 2005
Proof #45 of the Pythagorean theorem March 2, 2005
Coin Game February 22, 2005
What Is Geometry? February 10, 2005
Staircase Illusion February 9, 2005
Poggendorff's Illusion February 9, 2005
Wundt Block Illusion February 8, 2005
Wundt Illusion January 31, 2005
Dividing a Segment into N parts: Besteman's Construction II January 31, 2005
Dividing a Segment into N parts: Besteman's Construction January 30, 2005
Dividing a Segment into N parts: GLaD Construction January 29, 2005
Dividing a Segment into N parts: SaRD Construction January 7, 2005
Problem in an Equilateral Triangle II January 6, 2005
Property of the Powers of 2 January 4, 2005
Problem in an Equilateral Triangle
Copyright © 1996-2008 Alexander Bogomolny
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