Question

a cellular telephone tower casts a shadow that is 72 feet long. while a nearby tree that is 27 feet tall casts a shadow that is 6 feet long. how tall is the tower?

Answer 1

Shadow length is proportional to object height.
   (tower height)/(tower shadow length) = (tree height)/(tree shadow length)
   (tower height)/(72 ft) = (27 ft)/(6 ft)
   (tower height) = (72 ft)*(27/6)
   (tower height) = 324 ft

The cellular telephone tower is 324 ft tall.