As always, be sure to thoroughly test your code. You should test procedures individually and also together. In other words, be sure that images generated by procedures you write for 9.14 through 9.17 can be passed as argument(s) to other procedures.
The following file contains the code from the book relevant to the lab:
~mc27/labs/graphics/graphics-system.scmYou should copy it over into your directory to get started.
Once you have defined
make-filled-triangle, you can
uncomment the definitions of
nova-bb in the file. However, you have to put those
definitions after your definition of
make-filled-triangle. Once you have defined
make-stacked-image, you can also try evaluating
(show (pinwheel nova-bb))