The equation is:
$r^2=-4 \sin(2\theta)$
I first made a reference graph in cartesian coordinates using values $\displaystyle \frac{\pi}{4}$, $\displaystyle \frac{\pi}{2}$, $\displaystyle \frac{3 \pi}{4}$, $\displaystyle \pi$. Then from that I formed this:
Something seems off about that though. Should it be across the other axis instead?