Finding flux using polar coordinates.

Question

I solved exercise using polar coordinates. I thought that $x=rcos(\alpha)$ and $y=rsin(\alpha)$. In my exercise given. Given vector field and I solved it using divergence theorem. Result is: $\iiint$3dxdydz
$(x+2)^2$+$y^2$$\le$4;
$0$$\le$3y$\le$$\sqrt3$$(x+2)$;
$4(x+4)\le z \le 5(x+4)$
Here I took $(x+2)=rcos(\alpha)$ Is it true? or I should take only $x=rcos(\alpha)$ If I take $(x+2)=rcos(\alpha)$ answer is $2\pi+4$ but if I take $x=rcos(\alpha)$ I can't solve it. Please help me.