2. The second question is correct. Through direct calculation, a square of 12m has a side length of 3m and an area of 9m2. For example, a rectangle is 2 in length, 4 in width and 8m2 in area (in fact, the basis of this problem is a theorem: the mean value theorem, which is a three-level problem, so I won't elaborate on this theorem, which is beyond the level).
The third question is wrong. Not the same unit, so you can't compare the sizes.