[tex]\begin{gathered} \text{volume}=\pi r^2((\frac{4}{3})r+a) \\ r=\frac{8.4}{2}=4.2\text{ mm} \\ a=55.2\text{ mm} \\ \\ \text{volume}=\pi\times4.2^2(\frac{4}{3}\times4.2+55.2) \\ \text{volume}=\pi\times17.64(5.6+55.2) \\ \text{volume}=\pi\times1072.512 \\ \text{volume}=3367.68768mm^3 \\ \text{volume =}3367.7mm^3 \end{gathered}[/tex]
