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 $cm$)
The closed figure formed by an arc of a circle and the radii through its end points is called .........
In a circle with radius $10\, cm ,$ the area of a minor sector is $75 \,cm ^{2}$. Then, the length of the arc of that sector is $\ldots \ldots \ldots . . cm$.
Points $A$ and $B$ are distinct points on $\odot( O , r)$ and point $C$ on the circle lies in the interior of $\angle AOB$. Then, $\overline{AB}\cup \widehat{ACB}$ is ........
The length of the minute hand of a clock is $6\,cm .$ The area of the region swept by it in $10$ minutes is $\ldots \ldots \ldots \ldots cm ^{2}$. $(\pi=3.14)$