Answer:
12 inches
Step-by-step explanation:
To solve you have to set up a ratio. Because both buildings are being shrunk the exact same amount, you just have to account for the size difference from the miniature and real life. The ratio is 21:3 and 84:x. To find x you just have to cross multiply and solve.
The equation comes out to be 252 = 21x
Divide both sides by 21 to get x.
252/21 = 12
The size of the 84 foot building as a model is 12 inches.
