How big is a shadow?  That depends on a lot of different things.  Do the activity Shadows #2 to determine how the size of a shadow depends on the relationship between light source, object, and the surface on which the shadow appears. (Also see the set-up instructions "Shadows Inside" in the Set-Up section in your manual; for some notes about making graphs, go here.)

What property of light is responsible for the existence of shadows?
Draw a picture showing a tiny light bulb, a screen, and an object, which shows how a shadow is formed. Then draw another picture which shows why the shadow changes size when you move the object closer to the light source.
Here are our pictures -- but you draw yours first.
Science content: light and shadows