Check the picture below.
so let's find "x" or namely the base of the triangle, keeping in mind that the triangle has a height of 3, and that there are four of those triangles, then we'll get their area and the area of the green square and sum them all up.
![x=√(4^2 - 3^2)\implies x=√(7) \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\textit{\LARGE Areas}}{\stackrel{four~triangles}{4\left[\cfrac{1}{2}(\underset{b}{√(7)})(\underset{h}{3}) \right]}~~ + ~~\stackrel{square}{(√(7))(√(7))}}\implies 6√(7)+7 ~~ \approx ~~ \text{\LARGE 22.87}](https://img.qammunity.org/2023/formulas/mathematics/high-school/bsoeise8ku3xyn2tyja6pop0zwa9fz5hc7.png)