210 feet To answer this question you need to know the ratio of shadow with the actual object. In this case, 42 feet flagpole cast 9.4 feet shadow. Then the ratio is:
42feet/9.4 feet= 4.468
That means the actual height is 4.468 times of shadow length. After that, you can multiply the ratio with the shadow to know the object actual size. It would be: 47 feet x 4.468= 210 feet.