The length of the arch is 2× 2× 3.14 ÷ 2 = 6.28m.

The area of the arch shed is 6.28×20= 125.6 square meters.

The total area of plastic film is:125.6+6.28× 2 =138.16m2. The actual consumption is greater than this number, because the seam is to be pressed.

Vegetable area: 2×2×20=80 square meters.

Space in the greenhouse: 6.28×20= 125.6 cubic meters.