B$)$ Evaluate ${\displaystyle \underset{-3}{\overset{3}{}}}{\displaystyle \underset{-\sqrt[\phantom{2}]{9-x^2}}{\overset{\sqrt[\phantom{2}]{9-x^2}}{}}}{\displaystyle \underset{\sqrt[\phantom{2}]{9-x^2}}{\overset{3}{}}}\sqrt[\phantom{2}]{x^2+y^2}dzdydx($Hint: change to polar coordinate$)$