An architect created the blueprints for the chin's house. the scale factor is 1 inch: 40 inches. the length and width of the living room on the blueprint are 4 inches and 8 inches respectively. what is the area of the actual living room?

The measurements for the actual room are, in inches, 160 x 320

Step-by-step explanation:

If you want the computed area, then multiply those numbers together since A=bh.  I assumed you were just looking for the measurements of the actual room.  Set up a ratio for the scale first, the model info in the numerator and the actual room info in the denominator:

Here, the m is the model on paper and the a is the actual room.  So if the length of the room on paper is 4 inches, that will go on top with the model stuff and we will solve for the missing equivalent length of the actual room:

Cross multiply to get that the length of the actual room is 160 inches long. Divide by 12 if you need that number in feet.

Doing the same with the width:

Cross multiply to get that the width of the actual room is 320 inches.  Again, if you need that in feet, divide by 12.