The tree in your friend's yard casts a shadow that is 27 feet long. Your friend is 5 feet tall and casts a shadow that is 4.5 feet long. What is the height of the tree?

Set the equation up as a proportion, where x = the height of the tree in feet

27/x = 4.5/5

cross multiply

(4.5) (x) = (27) (5)

(4.5) (x) = 135

divide the entire equation by 4.5 to isolate x

135/4.5 = 30

x = 30

the tree is 30 ft tall