you are missing a dimension. Cubic means cubed i.e. 3. the unit is derived from multiplying metre by metre by metre. 1m x 2m gives you 2m2 (area). This cannot be associated without the third dimension.
The volume is 6.2832 cubic meters.
It's easier to put them into meters first so that's 2m x 2m x 0.1m = 0.4m^3
40 cubic meters
A meter is a measure of distance and a cubic meter is a measure of volume. The two units are incomparable. A cube which has a side length of 2 meters would have a volume of 2m * 2m * 2m = 8 cubic meters.
30 cubic meters
56.54866776 or 56.55 cubic meters to 2 d.p.
2m and 40cm
2m x 2m x 3m is equal to 12 m3 (cubic metres)12 m3 is equal to 423.776 ft3 (cubic feet)
None. Its a hole. But you would have removed 3 x 2 x 2 = 12 cubic meters of dirt, which is 120,000 cm3.
2m x 2m = 4 square meters
200cm=2m
The volume would be 211 or 2 cubic meters.