Indirect measurement. Explain why these triangles are similar, then solve for the height of the tree. Nadia has an eye height of 5 ft. She is standing 3 feet away from the mirror when she can see a tree’s reflection. She determines the tree is 21 ft away from the mirror. How tall is the tree?

Answer 1

light forms equal angles of incidence and reflection, so the triangles are similar. So he height h of the tree is found using

h/5 = 21/3