It I'd 12 multiplied by 9 aka 108.
108sf
135
8' x 9' = 72 square feet.
216 sq ft
12 x 9 = 108 ft2
9 x 11 = 99
16 by 9 is equal to 16 times 9....which is 144
Assuming the room is 9 ft by 14 ft (the question does not say so), the area would be 9*14 = 126 square feet
Assuming the room is 9 ft by 13 ft (the question does not say so), the area would be 9*13 = 117 square feet
For 9 ft x 20 ft = 180 ft²
863 Sq. Ft.
The square footage of the room is 9.5*10.5 = 99.75 square feet. The height of the room is irrelevant.