Editing Tangram (section)

== Number of configurations ==
[[Image:convex_tangram_shapes.svg|thumb|The 13 convex shapes matched with the tangram set]]
Over 6500 different tangram problems have been created from 19th-century texts alone, and the current number is ever-growing.{{sfn|Slocum|2001|p=37}} Fu Traing Wang and Chuan-Chih Hsiung proved in 1942 that there are only thirteen [[convex polygon|convex]] tangram configurations (segments drawn between any two points on the configuration are always completely contained inside the configuration, i.e., configurations with no recesses in the outline).<ref>
{{cite journal |author1=Fu Traing Wang |author2=Chuan-Chih Hsiung |date=November 1942 |title=A Theorem on the Tangram |journal=[[The American Mathematical Monthly]] |volume=49 |issue=9 |pages=596–599 |jstor=2303340|doi=10.2307/2303340}}</ref><ref name="isbn0-486-21483-4">{{cite book |author=Read, Ronald C. |title=Tangrams : 330 Puzzles |publisher=Dover Publications |location=New York |page=53 |isbn=0-486-21483-4 |year=1965}}</ref>