If that's supposed to be a square, just do the multiplication. The answer will be in square meters.
144 square meters
1600mm x 1600mm is 2.56 square meters.
9 square meters
18.39 square meters.
36 square metres
20 x 10 = 200 square meters.
500 x 315 = 157,500 square meters.
6.04 square meters.
20.07 square meters.
4.8m x 6.5 meters equates to 3,358.34 square feet.
20 m x 40 m = 800 square meters
312.5m2