For a rectangular gate $(ab)$ submerged in water as shown, the magnitude of the hydrostatic force acting on the gate can be calculated using $F_p\frac{?}{b}=ar(p)A,$ and the location of the center of pressure $(CP)$ can be calculated using $V_{CP}\frac{-}{b}ar(y)=\frac{\frac{?}{\text{b}\text{a}\text{r}}(1)}{(\frac{?}{\text{b}\text{a}\text{r}}(y))A},$ for the gate we know $a=3m,b=2m,=30,Y_{\text{w}\text{a}\text{t}\text{e}\text{r}}=9810\frac{N}{m^3},$ and the centroid of the gate is $1$ meter below the free surface verticallv. calculate the following values: the value of $A$ in unit of $m^2$