spiceDudeney’s Haberdasher puzzle

Author: Ivan De Winne


Implemented in:Portugal, Czech Republic and France

Description: The objective is to build up the students’ mathematical knowledge through problem solving, and to teach students to make geometric constructions by using GeoGebra, the tool for dynamic geometry. The lessons start with a short presentation of the problem, namely Dudeney’s dissection of an equilateral triangle into a square. After that the students have to cut a square into four pieces and create equilateral triangles. Furthermore, they have to do some online research on keywords such as Dudeney, Canterbury puzzles, hinged dissections, etc. Once this preparatory work is done, the students have to construct Dudeney’s puzzle with GeoGebra. They have to make calculations on the area of the triangle and the exact length of the sides of the square. After that the students are encouraged to compare their solutions with the actual solutions proposed by Dudeney in 1908 and to reconstruct Dudeney’s puzzle step by step with GeoGebra.

More information:Spice GP - Dudeney’s Haberdasher puzzle