Turn a solid, look at it from the front, the side and above, and unfold it into a net. Build with cubes, and decide whether a net really folds up into its solid.
Drag to turn Β· scroll or pinch to zoom Β· the arrows show where the front, side and plan views are seen from.
Tap a floor square or a face of a cube to add a cube; switch to Remove to take cubes away. Drag to turn.
Decide first, then fold it up to check. After you answer, faces that fold to the same place have the same colour; red faces land on top of another face.
The squares fold up along the edges they share. A net of a cube closes up with no gaps and no squares on top of each other.