\input zb-basic \input zb-matheduc \iteman{ZMATH 2015e.00001} \itemau{Wanko, Jeffrey J.; Nickell, Jennifer V.} \itemti{Reinforcing geometric properties with Shapedoku puzzles.} \itemso{Math. Teach. (Reston) 107, No. 3, 188-194 (2013).} \itemab Summary: Shapedoku is a new type of puzzle that combines logic and spatial reasoning with understanding of basic geometric concepts such as slope, parallelism, perpendicularity, and properties of shapes. Shapedoku can be solved by individuals and, as demonstrated here, can form the basis of a review for geometry students as they create their own. In this article, the authors trace the evolution of Shapedoku puzzles from their Sudoku ancestry, describe how one high school teacher introduces them into her geometry classroom, and highlight some high school students' work as they reason through their own creations. Activity sheets of puzzles created by high school students for teachers to use in their own classrooms are also provided. (ERIC) \itemrv{~} \itemcc{A20 G40} \itemut{puzzles; geometric properties; logical thinking; spatial reasoning; problem solving} \itemli{http://www.nctm.org/publications/article.aspx?id=39493} \end