Use cylindrical coordinates to calculate : $$\int\!\!\int\!\!\int _{\mathcal{W}} x^2+y^2\,dV\qquad \mathcal{W}: x^2+y^2\le 9 ,\quad 0\le z \le 12$$ $\int\!\!\int\!\!\int _{\mathcal{W}} (x^2+y^2)\,dV=$