Find the area of the following figure.

[tex]\\ \sf\longmapsto side=\dfrac{Diagonal}{\sqrt{2}}[/tex]
[tex]\\ \sf\longmapsto Side=\dfrac{3\sqrt{2}}{\sqrt{2}}[/tex]
[tex]\\ \sf\longmapsto Side=3cm[/tex]
Now
[tex]\\ \sf\longmapsto Area=(side)^2[/tex]
[tex]\\ \sf\longmapsto Area=(3)^2[/tex]
[tex]\\ \sf\longmapsto Area=9cm^2[/tex]