  We derive expressions for the critical density for jamming in a
hyper-rhomboid system of arbitrary shape in any dimension for the Kob-Andersen
and Fredrickson-Andersen kinetically-constrained models. We find that changing
the system's shape without altering its total volume or particle density may
induce jamming. We also find a transition between shapes in which the
correlation length between jammed particles is infinite, and shapes that have a
finite correlation length.
