Here are the problems on pages 271-272 due next class for anybody who needs them:

6.2.1 Using the Newell Method
For the three vertices (6, 1, 4), (2, 0, 5), and (7, 0, 9), compare the normal found using the Newell method with that found using the usual cross product. Then use the Newell method to find (n_x, n_y, n_z) for the polygon having the vertices (1, 1, 2), (2, 0, 5), (5, 1, 4), (6, 0, 7). Is the polygon planar? If so, find its true normal using the cross product and compare it with the Newell method.

6.2.3 Represent the generic cube
Make the vertex, normal, and face lists for the “generic” cube, which is centered at the origin, has its edges aligned with the coordinate axes, and has edges of length two. The eight vertices of this generic cube therefore lie at (-1, -1, -1), (-1, -1, 1), (-1, 1, -1), (-1, 1, 1), (1, -1, -1), (1, -1, 1), (1, 1, -1), and (1, 1, 1).

6.2.4 Faces with holes (***TRY***)
Figure 6.9 (6.11 in the book) shows how a face containing a hole can be captured in a face list. A pair of imaginary edges is added that bridge the gap between the outer edge of the face and the hole, as suggested in the figure.

The face is traversed so that (when walking along the outside surface) the interior of the face lies to the left. Thus a hole is traversed in the CW (clockwise) direction. Assuming we are looking at the face in the figure from its outside, the list of vertices would be: 5 4 3 8 9 6 7 8 3 2 1. Sketch this face with the additional hole in it, and give the proper list of vertices for the face. What normal would be associated with each vertex?