First keep in mind that 20 square kilometers is not the same as 20 kilometers squared. Conversion units will have to be squared as well.
Second, remember that there are exactly 2.54 centimeters in an inch, or 30.48 cm/ft.
Third, to convert from kilometers to centimeters, just multiply by a hundred thousand, or 105.
Put it all together and you get 20 x (105 / 30.48)2 = 215,278,208.334... square feet (or about 7.722 square miles).
20 x 20 = 400 square feet.
2.78 square feet.
20 x 19 = 380 square feet.
12 x 20 = 240 square feet.
20 square feet equates to 1.86 square meters.
20 feet = about 0.006096 kilometers.
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.
Answer: 20 km = 65,616.797 feet.
20 x 19 = 380 square feet.
12 x 20 = 240 square feet.
13 x 20 = 260 square feet.
20 square meters are 215.278208 square feet.
20 square feet equates to 1.86 square meters.