This worksheet serves as an introduction to forms. I use this to first show my students the difference between shapes (2-dimensional) and forms (3-dimensional).
The first space has the students draw and label 6 or shapes. The next two spaces, I have the students draw and label each of the five major forms (cube, sphere, cone, cylinder and pyramid) along with me; showing them how to generaly draw them as a "see-through" form and as a "solid" form.
This is a great way to introduce the element of art, Form, easing the students into it, especially when students can have so much trouble with it.