Is it possible to transform an equilateral triangle into a perfect square? In 1907, Henry Dudeney, an English writer and mathematician renowned for his mathematical puzzles, proposed it was possible using only four pieces connected to each other at “hinged” points along a chain. Without severing any of the connections, the chain can be folded from a triangle into a square (and vice versa).
* A haberdaher is someone who deals in small items and equipment for men’s clothing. Though, we couldn’t find specific information on what such a person has to do with the puzzle.
Gif courtesy of mathani.tumblr.com