Pete is standing 2 feet away from a mirror on the ground. Pete is 5 feet tall and can just see the top of the tree in the mirror from where he is standing. The two triangles formed in the picture above are similar.

Question

If the mirror is 12 feet away from the base of the tree, how tall is the tree?

Answer 1

If the two triangles are similar (and they are -- why?) then if the tree has height h,

h/12 = 5/2

Answer 2

12

Answer 3

18

Answer 4

16