Could MgCl2 possibly be gaseous in the question? It's not the usual state (bp 1 412 °C) so the assignment should necessarily mention it.
It's the only situation where I detect a sense in the assignment. As a solid or solution it's just meaningless.
With an angle in a Cl-Mg-Cl gaseous molecule (IF it vaporizes as triatomic molecules) it would be polar, just like H2O is. With 180°, no chance indeed.