Find the area of a square plot of land whose each side measures

Area of the square plot $=$ Side $\times$ Side $=(\text { Side })^{2}=a^{2}$ (Because the area of the square is $a^{2}$, where $a$ is the side of the square)

$=8 \frac{1}{2} \times 8 \frac{1}{2}$

$=\left(8+\frac{1}{2}\right) \times\left(8+\frac{1}{2}\right)$

$=\frac{17}{2} \times \frac{17}{2}$

$=\frac{17 \times 17}{2 \times 2}$

$=\frac{289}{4}$

$=72 \frac{1}{4} \mathrm{~m}^{2}$

Therefore, the area of the square plot is $72 \frac{1}{4} \mathrm{~m}^{2}$.