Multiply the two dimensions to get the area. The calculation will give you 400 square feet.
400 square feet
20ft² = 1.858m²
There are: 20 times 9 = 180 square feet
20 feet x 10 feet = 200 square feet
There are: 20 times 9 = 180 square feet
20ft * 15ft = 300 square feet.
20ft x 28ft = 560ft2
420 square feet. (21 x 20 = 420)
If each side of the square is 20-ft, then the area of the square is (20 x 20) = 400 square feet.
1 ft = 0.3048 m, 20 ft = 6.096 m, so a 20ft square is 37.16 sq m
Area of a circle in square feet = pi*radius2
12 ft x 20 ft = 240 sq. ft.