Exercises

Common problems

(rotate-45 img) does not work. You want (rotate 45 img). Notice the space before the 45.
How do you find out the RGB numbers for a color? The book has one method but I like (colorize "turquoise").
(star 30 40 "blue") produces a faint blue star, but I wanted regular blue. The 40 means fade to 40/255 of the color. You should put "solid" instead.

Fading increases by 5 each time.