Answer: 20 foot tall.
Step-by-step explanation: the shadow of the pole is 3 feet. and the shadow from the building is 12 feet.
12 can be divided by 3, 4 times. we know for every 3 foot shadow, the actual object is 5 feet tall.
we just multiply 5 by 4 to get 20.
we can also check our work by dividing 3 by 5. this is 0.6.
then we divide 12 by 20. that is also 0.6.
hence that is the answer.