$20-2.[20$ points$]$ For the composite area shown below, find the centroid $(\stackrel{}{x}$ and $\frac{?}{\text{b}\text{a}\text{r}}(y))$ and the moment of inertia about the $x-$axis $(I_x).$

$y$

Answer $-\stackrel{}{x}=88\mathrm{.}7mm\frac{,}{b}ar(Y)=37\mathrm{.}5mm,I_x=1\mathrm{.}78{10}^{7}m{m}^4$