Answer:
9 yards, assuming it is in the shape of a square.
Explanation:
We are not told anything about the shape of the room. Is it a rectangle, a square, a pentagon, etc.?
Lets assume is is in the form of a rectangle, with side length of L and width of W.
Area = L*W
81 yd^2 = L*W
This is as far as we can go to determine how much is in each side of the room. However, if we assume the room is square, we can find answers:
A square room means L = W
Area = L*W
Area = L*L or L^2
81 yd^2 = L^2
L = 9 yards