The diagonal of a square is given by :
[tex]s\sqrt[]{2}[/tex]
where s = side of the square.
From the problem, the area of the square garden is 128 m^2.
Solve for the side, s :
[tex]\begin{gathered} A=s^2 \\ 128=s^2 \\ s=\sqrt[]{128} \\ s=\sqrt[]{64\times2} \\ s=8\sqrt[]{2} \end{gathered}[/tex]
The diagonal will be :
[tex]\begin{gathered} d=8\sqrt[]{2}\times\sqrt[]{2} \\ d=16 \end{gathered}[/tex]
ANSWER :
16 m
