$2.40
In this worksheet you have three simple solid figures: a cylinder, a cube and a sphere. Starting from this linear drawing, you can deal with various topics at the same time: theory of the shadows, drawing techniques for shading, relationship between positive and negative space.
For this work are required only a soft pencil and a felt tip pen, but the variants may be many, such as colored shadows with pastels or different ways to decorate the background.