• Corpus ID: 3916812

# The Convex Configurations of "Sei Shonagon Chie no Ita" and Other Dissection Puzzles

```@article{FoxEpstein2014TheCC,
title={The Convex Configurations of "Sei Shonagon Chie no Ita" and Other Dissection Puzzles},
author={Eli Fox-Epstein and Ryuhei Uehara},
journal={ArXiv},
year={2014},
volume={abs/1407.1923}
}```
• Published 1 July 2014
• Mathematics
• ArXiv
The tangram and Sei Shonagon Chie no Ita are popular dissection puzzles consisting of seven pieces. Each puzzle can be formed by identifying edges from sixteen identical right isosceles triangles. It is known that the tangram can form 13 convex polygons. We show that Sei Shonagon Chie no Ita can form 16 convex polygons, propose a new puzzle that can form 19, no 7 piece puzzle can form 20, and 11 pieces are necessary and sufficient to form all 20 polygons formable by 16 identical isosceles right…
3 Citations

## Figures from this paper

• Mathematics
JCDCGG
• 2015
On the negative side, it is shown that the problem is strongly NP-complete even if the pieces are all polyominos, and on the positive side, the problem can be solved in polynomial time if the number of pieces is a fixed constant.
• Computer Science
• 2018
The set of the 16 possible convex tangrams that can be composed with the 7 so-called "Sei Shonagon Chie no Ita" (or Japanese) tans is considered and all essentially different solutions with the "Japanese" tans are presented.
The final author version and the galley proof are versions of the publication after peer review and the final published version features the final layout of the paper including the volume, issue and page numbers.

## References

SHOWING 1-4 OF 4 REFERENCES

• Mathematics, Education
• 1942
2. Lemmas. It is easily seen that the tangram can be divided into sixteen equal isosceles right triangles. For the sake of convenience, we call the legs and the hypotenuses of these right triangles

### http://www.matsusaki.jp/ local-event

• http://www.matsusaki.jp/ local-event
• 2014