Answer:
666.67 ft^2
Step-by-step explanation:
We start with a 4x5 scale room
We then use the 1:20 scale to multiply the 4 and the 5 by 20
4*20=80
5*20=100
We now have the dimensions of the actual room, 80in.x100in.
Area=length*width
A=100*80
A=8000 in^2
We are not done yet, though. To get feet, you convert inches to feet. 1 foot=12 inches.
8000/12=666.667, or 666.67, or 667, depending what you would round to