The actual room has an area of 166ft2 and one of the sides, s, measures 13ft. Side s corresponds to side m of your model and m = 2ft. In order for your model to have the same proportions as the actual room, what is the required area of your model room?
2/13 is the linear scaling needed for m to correspond to s.
The other side is also scaled by 2/13, so the area is scaled by 4/169.
4/169 * 166 = 3.93 ft^2