Speaker：Min Yan (The Hong Kong University of Science and Technology)

Time：2019-03-25 15:30

Location：Conference Room 105 at Experiment Building at Haiyun Campus

Abstract：To play the ball with n-sided shapes, n must be 3, 4, or 5. The jigsaw puzzle study of congruent triangles began in 1922 and was completed in 2002. The puzzle of congruent pentagons is much more complicated than that of triangles, and we have to consider five possible side length combinations: a2b2c, a3bc, a3b2, a4b, a5. We have completed the classification of four combinations, the only one that has not been completed is the almost equilateral combination a4b. Triangles are rigid and pentagons are flexible. For pentagon puzzles, we need to establish various techniques and theories, some of which are general and some for specific side length combinations. Some techniques and theories can be further developed into new research topics. This subject is a collaborative research with Akama Yoji of Tohoku University, Wang Erxiao and Lu Haiping of Hong Kong University of Science and Technology.