The Growing Triangle puzzle gives people two moves to make four triangles from these matches. ... To solve this problem you have to think in 3D instead of seeing them as flat shapes. 4.

It looks like someone’s discovered an interesting resale use for destroyed antiques: 3D puzzles. Though almost certainly a fake (would that real Ming Vases break into such neat pieces), the ...

The puzzle, which comes from a new book by London-based Alex Bellos, requires you to transform two triangles made from six matches into four triangles, by moving just two matches.

Henry Dudeney, a self-taught English mathematician and puzzle columnist, asked his readers to dissect an equilateral triangle into the smallest number of pieces that could be rearranged into a square.