The length of the minute hand of a clock is $7\,cm$. The area of the region swept by it in $20$ minutes is $\ldots \ldots \ldots \,cm^2$.

$A$ piece of wire $20 \,cm$ long is bent into the form of an arc of a circle subtending an angle of $60^{\circ}$ at its centre. Find the radius of the circle. (in $cm$)

Find the number of revolutions made by a circular wheel of area $1.54 \, m^2$ in rolling a distance of $176 \, m$.

The circumference of a circular ground is $352\, m$. Find the area of the ground (in $m^2$).

As shown in the adjoining diagram,the length of the side of the square plot $ABCD$ is $50 \, m$. At each vertex of the plot,a flower bed in the shape of a sector with radius $10 \, m$ is prepared. Find the area of the plot excluding the flower beds. $(\pi = 3.14)$ (in $m^2$)

As shown in the diagram,the side length of square $ABCD$ is $21 \ cm$. $\widehat{APC}$ is an arc of $\odot(B, BA)$ and $\widehat{AQC}$ is an arc of $\odot(D, DA)$. Find the area of the shaded portion. (in $cm^2$)