Check the picture below.
well, the volume of the craft prism will simply be length * width * height, and we know that is 7140.
[tex]\textit{volume of a rectangular prism}\\\\ V=Lwh ~~ \begin{cases} L=length\\ w=width\\ h=height\\[-0.5em] \hrulefill\\ L=17\\ h=28\\ V=7140 \end{cases}\implies \begin{array}{llll} 7140=(17)w(28)\implies \cfrac{7140}{(17)(28)}=w \\\\\\ 15=w \end{array}[/tex]
we know the area of the top is just w * 17, and the circle is just 2/5 of that, well that's just
[tex]\cfrac{2}{5}(15)(17)\implies (2)(17)\cfrac{15}{5}\implies (2)(17)3\underset{\textit{area of the circle}}{\implies 102~in^2}[/tex]
