Check the picture below.
so if we peel off the cylinder, we end up with that, hmmm how long is the width? well, we know the circular bases have a diameter of 9mm, so half that is its radius or 4.5mm, and if we peel off the circle, we'll end up with a long line whose length is its perimeter or namely its circumference, which oddly enough is the length of the width
![\textit{Circumference of a circle}\\\\ C=2\pi r ~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ r=4.5 \end{cases}\implies C=2\pi (4.5)\implies C=9\pi \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\textit{\LARGE Lateral Area}}{\stackrel{width}{(9\pi )} \stackrel{height}{(17)}} \implies {\Large \begin{array}{llll} 153\pi \end{array}} ~mm^2](https://img.qammunity.org/2024/formulas/mathematics/high-school/4fkd3d0cbyuxge6j5h5g8zdj5xfpdbs0as.png)