Third Grade Geometry 1 - Polygons Powerpoint Lesson is powerful when used as direct instruction in the classroom, online, or individually. It teaches students about polygons. They learn the definitions, how to identify them, and what they look like. In addition, the characteristics of members of the polygon family are presented: triangle, quadrilateral, pentagon, hexagon, octagon. Memory tips are given to help students remember. There are 22 strategies of effective teaching based on researc