Today’s three challenges are from Han Dongkyu, a talented young puzzle designer from South Korea. The first two will warm you up for the third, which is probably the most stunning example of a dissection puzzle I have ever seen. Prepare to be awed – and have your brain twisted inside out.
1. Librarian’s Nightmare Part I
Divide the shape below, which looks like an open book, into two identical pieces. (In other words, if the shape was made of paper, how do you cut it so that you get two identical pieces with no extra material left over. Pieces may be flipped over.)
Now divide the shape into three identical pieces.
2. Librarian’s Nightmare Part II
Divide the following shape (the book and the hands) into two identical pieces. Again, the pieces may be flipped over.
These first two were variations on puzzles you may have seen before. The next one takes the genre to the next level. It’s an extremely ingenious take on castling in chess. Marvel at its humour and elegance – and best of luck!
3. Castling
Cut the first shape below into two pieces, in such a way that they can be rearranged to make the second shape. The pieces can be flipped.
Isn’t it brilliant? So clever.
If you would like to print out a copy of these puzzles, on which to draw the cuts, this link is to a pdf. The pdf also contains some hints on how to solve them.
I’ll be back at 5pm UK with the solutions. PLEASE NO SPOILERS
Han Dongkyu is a student at the Ulsan National Institute of Science and Technology, majoring in Computer Science & Engineering. His website is queuedlab.com
In other South Korea news, on Saturday October 9 the country celebrates Hangul Day, an annual holiday that celebrates Hangul (한글), the writing system used for the Korean language, which was devised in the fifteenth century by a team of scholars and is widely praised by linguists as the most perfect and scientific script in common use in the world. I’m not aware of another country that celebrates its writing system with a public holiday, so three cheers for South Korea and Hangul! Forgive me the blatant plug, but if you are interested in finding out why the script is so amazing, and tackling a puzzle in which you must decipher some common Korean words, you will find one in The Language Lover’s Puzzle Book, my most recent book, which is out in paperback this week.
I set a puzzle here every two weeks on a Monday. I’m always on the look-out for great puzzles. If you would like to suggest one, email me. I also give school talks about maths and puzzles (restrictions allowing). If your school is interested please get in touch.