$A$ circular pond has a diameter of $17.5 \, m$. It is surrounded by a $2 \, m$ wide path. Find the cost of constructing the path at the rate of $Rs. \, 25$ per $m^2$ (in $Rs.$).

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 diameter of a circle with area $154\,cm^{2}$ is $\ldots \ldots \ldots . cm$.

In a circle with centre $O$,$\overline{OA}$ and $\overline{OB}$ are radii perpendicular to each other. The perimeter of the sector formed by these radii is $75 \, cm$. Find the area of the corresponding minor segment. (in $cm^2$)

In a circle with radius $30\,cm$,a minor arc subtends an angle of measure $60^{\circ}$ at the centre. Then,the area of the minor sector formed by that arc is $\ldots \ldots \ldots \ldots$ $cm^{2}$. $(\pi = 3.14)$

Is the area of the circle inscribed in a square of side $a \, cm$ equal to $\pi a^2 \, cm^2$? Give reasons for your answer.