One of the things I really enjoyed about my Geometry classes in college was that they were very hands-on. We used a variety of manipulatives to explore geometric concepts, and the lessons have stayed with me for a long time now. I carried many of these ideas into the classroom when I started teaching, using ideas as simple as nets and tools like marshmallows and toothpicks. While these models are adequate for teaching the general ideas, they lack the consistency and formality that Geofix shapes offer.
Geofix shapes are a powerful tool for addressing many geometric concepts in the classroom. From something as simple as shape recognition to creating complex 3-D figures, these click-together shapes provide a hands-on tool that brings math to life. While they have a variety of uses, we'll look at three easy ways to implement the shapes: decomposing composite figures, relating perimeter and area, and understanding the relationship between 2-D and 3-D figures.
Decomposing Composite Figures
Composite 2-dimensional figures present unique challenges for students. It is often difficult to see that a complex figure is really just two or more basic shapes put together. Consider this simple example:
Providing students with outlines of composite figures and having them use the Geofix shapes to construct the figures helps students to see the relationship between the basic shapes and composite figures.
Relating Perimeter and Area
Give students three or four of the same basic shape. Point out that the area of each Geofix shape does not change, so the total area of three or four shapes put together will always be the same. Then ask students to create at least two different composite figures with their Geofix shapes and compare the perimeters of their figures. Encourage students to discuss their results and challenge them to find the composite shapes with the least and greatest perimeters.
Understanding the Relationship between 2-D and 3-D Figures
Give students a net diagram and have them build the 2-dimensional net. Then have them fold the net to create the 3-dimensional model it represents. After students have completed their 3-D model, challenge them to unfold the model to create a different 2-D net than the one they started with. Have them discuss their results and encourage them to find as many different nets as they can.
As students work with the Geofix shapes, they will become more familiar with the relationships between the shapes and build confidence with their understanding of geometry. They'll also create some meaningful memories that will stick with them for years to come.