The perimeter of rectangle = 90 + 70 + 90 + 70

= 140 + 180 = 320

Therefore, the perimeter of the square is also 320.

i.e: 320/4 = 80m p/s

Therefore, area of square = 80m x 80m = 1600 sq.cm

And, area of rectangle = 90m x 70m = 6300sq.cm.

The difference between the areas of both plots of land is:

6300 - 1600 = 4700.

Therefore, the area of the rectangular field was greater by 4700 sq.cm