How do you convert  (8, pi/2) into rectangular coordinates?

color(purple)(x = 0, y = 8
$r , \theta = 8 , \frac{\pi}{2}$
$x = r \cos \theta = 8 \cdot \cos \left(\frac{\pi}{2}\right) = 0$
$y = r \sin \theta = 8 \cdot \sin \left(\frac{\pi}{2}\right) = 8$