Patterns and Relationships: Struts 'n Stuff

In this math lesson, learners identify the relationship between the number of sides in a regular polygon and the number of struts needed to make each polygon rigid. Learners build polygons using strips of paper and paper fasteners to explore the attributes of triangles, rectangles, pentagons, and hexagons. From their explorations, learners discern that triangles form the only rigid polygon. Learners are then challenged to determine the least number of struts or supports they would need to add to the rectangles, pentagons, and hexagons to make them rigid. Learners record their findings in a chart and look for patterns. They use the pattern to state a rule that shows the relationship between the number of sides in a polygon and the number of struts needed to make it rigid. To further reinforce these concepts, learners make a graph showing this relationship. Learners use the graph to predict the number of struts needed to make different polygons rigid. Finally, the group discusses the relationship between the number of sides of a polygon and the number of triangles formed by the struts. Learners look for a pattern in order to make a generalization.