The total mileage of expressways in a province is 1400km. If the subgrade width is 50m, how many square meters is the area of expressways in this province? How many square kilometers?

The total mileage of expressways in a province is 1400km. If the subgrade width is 50m, how many square meters is the area of expressways in this province? How many square kilometers?

1400km * 50m = 1400000 * 50 = 70000000m2 = 7000 km2