SOLUTION: a boy who is 5ft. tall cast a shadow that is 12 ft. long. at the same time, a building nearby cast a shadow that is 72 ft. long. how tall is the building ?

Algebra ->  Test -> SOLUTION: a boy who is 5ft. tall cast a shadow that is 12 ft. long. at the same time, a building nearby cast a shadow that is 72 ft. long. how tall is the building ?      Log On


   

Question 790751: a boy who is 5ft. tall cast a shadow that is 12 ft. long. at the same time, a building nearby cast a shadow that is 72 ft. long. how tall is the building ?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
(length of shadow)/(height of object) = (length of shadow)/(height of object)

12/5 = 72/x

12x = 5*72 ... cross multiply

12x = 360

x = 360/12

x = 30

So the building is 30 feet tall.