There are lots of fun things you can do to find out more about shadows.
Try making your shadow as small as you can, and then as big as you can. Can you change the shape of your shadow? Try making it go up steps or around a corner.
Stand with your shadow in front of you. Can you touch your shadow head with your real hand, or step on your shadow head with your real foot? Try shaking shadow hands with the person next to you without touching your real hands.
Try doing shadow outlines early or late in the day to create huge, distorted shadows. Or try tracing shadow silhouettes of other objects, like bicycles or playground structures.
If you trace the same object at regular intervals (every 20 minutes, for instance) using a different color each time, you can create a beautiful piece of art!