What is the area (in $cm^2$) of a square inscribed in a circle of radius $8 \, cm$?

The length of a diagonal of a square inscribed in a circle with radius $10\, cm$ is $\ldots \ldots \ldots . cm$.

Three circles each of radius $3.5\, cm$ are drawn in such a way that each of them touches the other two. Find the area enclosed between these circles. (in $cm^{2}$)

The area of a square inscribed in a circle of radius $35 \, cm$ is $\ldots \ldots \ldots \ldots cm^{2}$.

While calculating the area of a circle,its radius was taken to be $6 \, cm$ instead of $5 \, cm$. The calculated area is $\dots \%$ more than the actual area.

In the figure,a square of diagonal $8\, cm$ is inscribed in a circle. Find the area of the shaded region.