Plot polar points and interpret a complex multiplier

The numbers $z_1,z_2$ satisfy $|z_1|=4$, $\arg z_1=\pi/3$, $|z_2|=2$, $\arg z_2=-\pi/6$.

(i) On an Argand diagram with origin $O$, mark their points and deduce the exact value of $|z_1-z_2|$.3 marks

(ii) Write down a number $a$ such that $z_1=az_2$. Hence or otherwise describe their geometric relationship.2 marks