Cut a Greek cross into four pieces, and refold it into a perfect square
A Greek cross — five equal squares arranged in a plus shape — sits on your table. Using only four straight cuts, can you slice it into pieces that reassemble, edge to edge with no gaps or overlaps, into one solid square?
Reveal the answer
Yes. The classic four-piece solution cuts along lines that meet the cross's outline at specific points found by construction, so the pieces pivot into a square with no waste — a case of the broader family of 'dissection puzzles' where one shape is cut into the fewest pieces that reassemble into another. It appears in Henry Dudeney's puzzle collections and was later catalogued in Martin Gardner's Scientific American column on polygon dissections (November 1961).
— Henry Dudeney (ed. Martin Gardner), 536 Puzzles and Curious Problems — Scribner, 1967, 'Geometrical Problems: Dissection Puzzles'
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