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Mathematical Treasure: Circle Packing in Edo Period Japan

Frank J. Swetz (Pennsylvania State University)

Gomei sanpo (1826) was a collection of sangaku problems attributed to the mathematician Iesaki Yoshiyuki and assembled by publisher Osakaya Mokichi. This is the title page of the book.

Imaginative problem situations involving fitting circles into fans, i.e. circle-packing in fan-shaped regions:

More typical problems involving circle packing and stacking:

For another set of sangaku problems, see Mathematical Treasure: Japanese Temple Mathematics, by Frank J. Swetz, here in Convergence.

These images are presented through the kind cooperation of the National Diet Library, Japan, and are used with permission. They were obtained from the library’s digital gallery exhibit, Japanese Mathematics in the Edo Period, where a complete examination and viewing of the item presented above can be found.

Index to Mathematical Treasures

Frank J. Swetz (Pennsylvania State University), "Mathematical Treasure: Circle Packing in Edo Period Japan," Convergence (July 2018)