the dimension of edge A is
[tex]10-3=7\operatorname{cm}[/tex]the dimension of edge B is
[tex]12\operatorname{cm}[/tex]the volume of the composed figure is
[tex]\begin{gathered} V1=3\times8\times12=288 \\ V2=12\times28\times7=2352 \\ \text{Vfigure}=288+2352=2640\operatorname{cm}3 \end{gathered}[/tex]Volume is 2640 cubic centimeters