For a coordinate system located at the centroid, calculate the maximum and minimum values of the moments of inertia $I_{\text{m}\text{a}\text{x}}$ and $I_{\text{m}\text{i}\text{n}}($obtained by rotating the axes$)$ and the corresponding angles of the section shown in Fig. $3.$ Use $a=80mm,b=0\mathrm{.}8a,$ and $t=14mm.$

Fig. $3$