You and a friend are playing a game of squirt-gun tag in a maze. Suddenly you see your friend's image in a small planar mirror (see illustration). You take a shot over the barrier in front of you and find that your friend is just at the end of the 7.0 m range of your squirt gun. If you are 4.0 m from the point of reflection of the light ray, how far from the point of reflection of the light ray is your friend?
The task is not clear without illustration. Please provide us with it or with link to it.