Haberdasher's Puzzle

Interactive recreation of the Haberdasher's problem

Maths Geometry Puzzle

This equilateral triangle has been carefully split into four pieces. Drag, drop and rotate the pieces to turn the triangle into a perfect square.

This puzzle was first solved by Henry Dudeney in 1903, and is named the Haberdasher's puzzle because the four shapes bear a resemblance to pieces of cloth you might find in a haberdashery (a shop selling bits and pieces related to sewing). This type of puzzle is called a dissection puzzle.

Anyone finding the above puzzle interesting, may also be interested in a number of books by Professor Greg N. Frederickson dedicated to similar geometric puzzles.