Sketchbook work for Michaels class, sphere and some cube drawings, its all about those shadows! 😉
‘The Dimensions of colour’ webpage by David Briggs has some great articles; I found this whilst researching into lighting spheres. Theres also other great articles found on his page.
Briggs has included some useful interactive spheres where you can change the direction of light. Handy tool when studying light and shadow. (Link above)
(Image above; Copyright. David Briggs)