Rigid foldability of the waterbomb tube with an odd . (a) Top half of a longitudinal strip in a waterbomb tube. is the equator of the tube. Vertices above the equator are marked as ,, and , while those below are marked as ,, and , in which . (b) The front view of a waterbomb tube with the equatorial row 0 and rows immediately adjacent to it and the top view of the equatorial row. One of the bases on the equatorial row is shown in blue. is the center of the tube. (c) Variation of nondimensional radii of vertices ,, and () of a tube with ,, and with respect to the folding angle and five representative configurations I to V of the tube in front and top views. The corresponding angles are listed below the configurations. Also see SM Movie S1.