The Mysterious Polygon task involves several components. Students initially work in small groups to create a polygon on large grid paper using the provided task cards that contain a system of inequalities. Students then complete a handout by participating in a gallery walk in the classroom viewing all created graphs. The handout asks students to identify each polygon using their knowledge of parallel and perpendicular lines and slope. Students work with a partner on the gallery walk handout and then complete provided problems on their own to further show understanding. A short assessment is included along with a rubric for scoring student level of mastery. Enrichment suggestions are provided that can extend the task to include finding distances on the coordinate grid.