Sharing Teaching Ideas: Why Not Three Dimensions?

When I reviewed our high school curriculum, I realized that my students did not have enough practice with situations that required analysis in three dimensions. Few situations that applied the threedimensional ideas studied in geometry were found in second-year algebra and precalculus, and calculus students faced with rotations that produced solids had very little experience to help them with the visualizations required. As a response, I developed several projects that I integrated into my courses at all three levels. What follows are descriptions of a three-year sequence of projects that help to develop students' spatial skills. The photographs are all examples of student-produced work.