How would you describe the shape of a loaf of bread? What about the shape of a very thin slice from that loaf? Such simple everyday objects or tasks may not seem to have much to do with math, but this is the very concept that the activity Cross-sections of Three-Dimensional Figures covers.
The activity begins with a review of the names of two- and three-dimensional shapes since students need to identify and describe the two-dimensional shapes that result from different cross sections of three-dimensional shapes. The 3-D shapes are primarily rectangular prisms and rectangular pyramids.
In the activity, students are able to rotate these figures to get a complete view of all faces, and are provided clear illustrations of different cross-sections. Cross-sections vary from being parallel or perpendicular to the base of the 3-D object, to being cut at different angles. Students also generalize about the resulting shape of the cross-section depending on the “cut.”
Click here to try : Geometry and Measurement – Cross-Sections of Three-Dimensional Figures