How would I use polar form to show
$$(-1-i\sqrt{3})(-4\sqrt{3}+4i)=8\sqrt{3}+8i$$
I tried putting it in polar form. And I got
$$2(\cos(225)+i\sin(225))(2\sqrt{7}\cos(150)+i\sin(150))$$
But I keep getting an incorrect answer can any kind soul show me how to solve this problem?