We have that the scale is 1 inch : 4.5 feet, this means that 1 inch equals 4.5 feet in reality, so if the model is 12 inches tall, we have a simple rule of three:
[tex]\begin{gathered} 1\text{ inch : 4.5ft} \\ 12\text{ inches : ? ft} \\ \Rightarrow\frac{(12\text{inches)}\cdot(4.5ft)}{1\text{inch}}=54ft \end{gathered}[/tex]Therefore, if the model is 12 inches tall, then the actual building is 54 feet tall.
