Fig. 13.

A $k=3$-turn, gap 1, spiral on the triangular grid $G_{▵}$, as defined in Definition 34. The centre of the spiral is at (0,0), and the arms of the spiral turn anti-clockwise while keeping at a distance (gap) of exactly 1 from each other. The monomers framed in red are those which reside in the “almost rectangle” $R_{k^{\prime }}=R_2$ in Definition 34