let's firstly convert the mixed fraction to improper fraction.
[tex]\bf \stackrel{mixed}{5\frac{2}{3}}\implies \cfrac{5\cdot 3+2}{3}\implies \stackrel{improper}{\cfrac{17}{3}} \\\\[-0.35em] ~\dotfill\\\\ \textit{area of a triangle}\\\\ A=\cfrac{1}{2}bh~~ \begin{cases} b=base\\ h=height\\ \cline{1-1} b=\frac{17}{3}\\ h=3 \end{cases}\implies A=\cfrac{1}{2}\left( \cfrac{17}{~~\begin{matrix} 3 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~} \right)(~~\begin{matrix} 3 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~) \\\\\\ A=\cfrac{17}{2}\implies A=8\frac{1}{2}[/tex]
