Illustration of tangram
tangram
noun
tan·gram ˈtaŋ-grəm 
ˈtan-
: a Chinese puzzle made by cutting a square of thin material into five triangles, a square, and a rhomboid which are capable of being recombined in many different figures
Example Sentences
Recent Examples on the Web Tangrams Plus Tangrams Plus is based on the ancient Chinese tangram puzzles. 
cleveland, 16 Mar. 2020 Each branch has a set of large tangram blocks — interlocking pieces that can be built with and used as movable seats. Katherine Nails, Philly.com, 21 June 2018 Math activities in the classroom featured the creation of math tangram puzzles, math scavenger hunts, math puzzles, etc. Julie A. Short/special To Cleveland.com, cleveland.com, 29 Dec. 2017
cleveland, 16 Mar. 2020 Each branch has a set of large tangram blocks — interlocking pieces that can be built with and used as movable seats. Katherine Nails, Philly.com, 21 June 2018 Math activities in the classroom featured the creation of math tangram puzzles, math scavenger hunts, math puzzles, etc. Julie A. Short/special To Cleveland.com, cleveland.com, 29 Dec. 2017 Word History
Etymology
perhaps from Chinese (Beijing) táng Chinese + English -gram
First Known Use
1818, in the meaning defined above