In a circle with radius $14 \, cm$,$\overline{OA}$ and $\overline{OB}$ are radii perpendicular to each other. Then,the area of the minor sector corresponding to $\angle AOB$ is $\ldots \ldots \ldots \, cm^2$.

Find the circumference and the area of a circle with diameter $42 \, cm$.

If $\theta$ is the angle (in degrees) of a sector of a circle of radius $r$,then the area of the sector is:

The areas of two sectors of two different circles with equal corresponding arc lengths are equal. Is this statement true? Why?

In $\odot(O, r)$,chord $\overline{AB}$ subtends a right angle at the centre. The area of the minor segment $\overline{AB} \cup \widehat{ACB}$ is $114 \, cm^2$ and the area of $\Delta OAB$ is $200 \, cm^2$. Then,the area of the minor sector $OACB$ is ......... $cm^2$.

The ratio of the radii of two circles is $4: 5$. Then,the ratio of their areas is...........