Easy. Just multiply 50 x 20, which equals 1,000 square feet.
50 x 20 = 1000 So the yard is 1000 square feet
The biggest diameter that would fit is 20 ft.
20 x 20 = 400 square feet.
400 square feet.
Do you mean a real square with the side length of 20 feet? Then 20 feet times 20 feet is 400 square feet.
400 square feet
2.78 square feet.
13 x 20 = 260 square feet.
20 x 19 = 380 square feet.
12 x 20 = 240 square feet.
20 square meters are 215.278208 square feet.
20 square feet equates to 1.86 square meters.