a HEXA=6, gon, has 6 sides, and we know the perimeter, all sides added up, is 70, so one side is just 70/6, or 35/3
[tex]\bf \textit{area of a polygon}\\\\
A=\cfrac{1}{4}ns^2\ cot\left( \frac{180}{n} \right)\qquad
\begin{cases}
n=\textit{number of sides}\\
s=\textit{length of one side}\\
\frac{180}{n}=\textit{angle in degrees}\\
----------\\
n=6\\
s=\frac{35}{3}
\end{cases}
\\\\\\
A=\cfrac{1}{4}\cdot 6\cdot \left( \frac{35}{3} \right)^2\cdot ot\left( \frac{180}{6} \right)[/tex]
