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

In a circle with radius $42 \ cm$,a minor arc subtends an angle of $60^{\circ}$ at the centre. Find the area of the minor sector and the minor segment corresponding to this arc. (Use $\sqrt{3} = 1.73$)

In $\odot(O, r)$,minor arc $\widehat{ABC}$ subtends a right angle at the centre. The area of the minor segment formed by $\widehat{ABC}$ is $14.25\,cm^2$ and the area of $\Delta OAC$ is $25\,cm^2$. Then,the area of the minor sector formed by $\widehat{ABC}$ is $\ldots \ldots \ldots cm^2$.

The radius of a circular ground is $56 \, m$. Inside it, a road of width $7 \, m$ runs all along its boundary. Find the area of this road in $m^2$.

If the area of a circle is $154 \, cm^2$,then its perimeter (circumference) is (in $cm$):

From a circular metallic sheet with radius $21\, cm$,a regular hexagon of side $21\, cm$ is cut off. Find the area of the remaining sheet. $(\sqrt{3} = 1.73)$ (in $cm^2$)