posted by Bob .
A man who is 6 ft tall is standing in front of a plane mirror that is 2 ft in length. If the mirror is placed lengthwise with its bottom edge 4 ft above the floor on a wall that is 5 ft away, how much of his image (i.e. what length of himself) can the man see? (Assume that his eyes are right at the top of his head). How much of the 8 ft-tall tree behind him, 10 ft away from the wall, can he see? When the man moves to stand next to the tree, with the mirror staying in place, how much of himself can he now see? How much of the tree can he now see?
a man can see upper 4 ft of his height, i.e. 2/3 of his height in the both locations.