Which of the following is not the net of the cuboid?

1. Analyse Net (1)

Net (1) has a central row of 4 alternating long and short rectangles, which form the lateral faces of the cuboid. The two flaps (one top, one bottom) are attached to different rectangles in the central row. When folded, they will form the top and bottom bases without overlapping. Thus, Net (1) is a valid net.

2. Analyse Net (2)

Net (2) has a central row of 4 alternating rectangles. The two flaps are both attached to the top of the central row, but on different rectangles (one long, one short). When folded, these flaps will form the top and bottom bases (one will fold over to become the opposite face). Thus, Net (2) is a valid net.

3. Analyse Net (3)

Net (3) has a central row of 4 alternating rectangles. There is one flap on the top and two stacked flaps on the bottom. A cuboid only has 6 faces, but this net has $4 + 1 + 2 = 7$ faces. Furthermore, the two stacked flaps on the bottom will overlap when folded. Thus, Net (3) is not a valid net.

4. Analyse Net (4)

Net (4) has a central row of 4 alternating rectangles. The two flaps are attached to the top and bottom of the same rectangle in the central row. When folded, they will form the top and bottom bases without overlapping. Thus, Net (4) is a valid net.