[tex]\bf \begin{array}{clclll}
(-7&,&\frac{5\pi }{3})\\
\uparrow &&\uparrow \\
r&&\theta
\end{array}\qquad
\begin{array}{clclll}
(x&,&y)\\
\downarrow &&\downarrow \\
r\cdot cos(\theta)&&r\cdot sin(\theta)
\end{array}[/tex]
so.. to get the x,y coordinates, or rectangular ones, get the cosine and sine of that angle, and multiply it times the "r"adius