Thomas' Calculus 13th Edition

$\frac{\pi}{2}\leq \Theta \leq 2\pi$ ,$0\leq r \leq 9$
describing the given region in polar coordinates of the graph below as $x^2+y^2=9^2$ => $r=9$ => $\frac{\pi}{2}\leq \Theta \leq 2\pi$ ,$0\leq r \leq 9$