Fold the paper so that it reach the given shape.
David Mitchell's (England) website contains a lot of paper folding-related puzzles.
- Identify which arrangement mountain folds and valley folds are valid. (from WPC 2017)
- Identify the correct crease line when the paper is folded into the given shape. (from WPC 2017)
History of the puzzle
Although Origami as a toy existed in Japan for at least 600 years, its application to geometry was first described by T. Sundra Rao (India) in 1893. Huzita–Hatori axioms are an axiomatised form of paper folding, described in 1991. The problem that asks whether a given fold pattern can be folded into a flat surface is shown to be NP-complete in 1996. 
Appearances in the past WPCs
- WPC 2017/Round 17 by Rohan Rao, Amit Sowani