This puzzle consists of four hinged pieces which can be folded one way to a square and the other way to an equilateral triangle. Master puzzler Henry Dudeney demonstrated a wooden model before the London Royal Society in 1905.
Mystifying geometry.
This puzzle consists of four hinged pieces which can be folded one way to a square and the other way to an equilateral triangle. Master puzzler Henry Dudeney demonstrated a wooden model before the London Royal Society in 1905.
Mystifying geometry.