Polygons, Angles and Trusses, Oh My!
The Eiffel Tower in Paris, France, is a well-known truss structure.Copyright 2016 Anthony-X, Pixabay CC0 {PD} https://pixabay.com/en/tower-eiffel-paris-eiffel-tower-1328833/
Students take a close look at truss structures, the geometric shapes that compose them, and the many variations seen in bridge designs in use every day. Through a guided worksheet, students draw assorted 2D and 3D polygon shapes and think through their forms and interior angles (mental “testing”) before and after load conditions are applied. They see how engineers add structural members to polygon shapes to support them under compression and tension, and how triangles provide the strongest elemental shape. A PowerPoint® presentation is provided. This lesson prepares students for two associated activities that continue the series on polygons and trusses.
Civil engineers design buildings, roads, bridges and dams and work in arenas such as transportation, water resources, surveying and construction. Much of their work involves the design of strong and safe structures, often employing creative truss designs that are original compositions of geometric forms. Like engineers, students explore the importance of testing—a key step in the engineering design process. The exploration of how trusses contribute to strong bridges illustrates how geometry figures into engineering designs that account for the anticipated loads from traffic, weather conditions and materials weight.
After this lesson, students should be able to:
- Identify trusses in a bridge structure.
- Describe the different shapes that form truss structures.
- Record measurements of interior and exterior angles.
- Discuss how polygon shapes are used and analyzed in engineering