CoachA shadow is the dark patch that appears behind a thing that blocks the light. Light cannot go through your body, so behind you the ground gets no light from the Sun: that dark you-shaped patch is your shadow.
Examples
Example 3.7 (Try it: shadow animals)
With the lamp of Method 3.6, put your hands in the light instead of a toy: two fingers up make rabbit ears, both thumbs crossed make a flying bird. The wall shows the shape your hands cut out of the light — a shadow always keeps the shape of its blocker, seen from the lamp.
Example 3.9 (Which side is the shadow on?)
In the morning, the Sun is on one side of you and your shadow lies on the other side. Face the Sun: your shadow hides behind you. Turn your back to the Sun: your shadow stretches out in front. The shadow always sits exactly opposite the source.
Example 3.10 (Try it: chalk around a shadow)
On a sunny morning, stand still in the playground while a friend draws a chalk line around your shadow. Come back after lunch and stand on the same spot: your shadow has moved out of its chalk line and changed its length! The Sun changed its place in the sky — and the shadow followed. The next chapter follows the Sun through its whole day.