20 x 20 = 400 square feet.
800 square feet (40 x 20 = 800).
2.78 square feet.
20' x 60' = 1,200 square feet.
16 feet X 20 feet = 320 square feet
20 x 19 = 380 square feet.
13 x 20 = 260 square feet.
12 x 20 = 240 square feet.
400 square feet (20 x 20 = 400).
13 x 20 = 260 square feet (13 and 20 must be in feet)
400 square feet (20 x 20 = 400)
400 square feet.