Congratulations on making it through another intense chapter! We learned all about generating triangle strips and triangle fans and how to put them together into objects. We also learned how to encapsulate the drawing calls when building these objects so that we can easily tie them together into a single command.
We also introduced the idea of a matrix hierarchy: one matrix for the projection, one for the camera, and one to move objects around in the world. Splitting things up in this way makes it easier to manipulate the scene and move stuff around.