Answer:
12 inches
Explanation:
Let be "x" the top inches (in the model) of a eighty four foot building.
According to the information provided in the exercise, we be aware of that the top of a two-story establishing is 21 toes and in the scale model its top is 3 inches.
Knowing this, we can set up the following proportion: 3/21=x/84
The final step is to get to the bottom of for "x" in order to calculate its value.