Area of a circle is $5544 \, cm^{2}$. Find its radius (in $cm$).

Find the area of a sector of a circle of radius $21 \, cm$ and central angle $120^{\circ}$. (in $cm^{2}$)

The length of the minute hand of a clock is $14 \, cm$. Find the area of the region swept by it between $10.10 \, AM$ to $10.30 \, AM$.

The area of a circle is $3850 \, cm^2$. In that circle,the length of an arc subtending a right angle at the centre is $\ldots \ldots \ldots \, cm$.

The ratio of the areas of two circles is $25: 36$. Then,the ratio of their circumferences is:

In $\odot(O, 12)$, minor $\widehat{ACB}$ subtends an angle of measure $30^{\circ}$ at the centre. Then, the length of major $\widehat{ADB}$ is $\ldots \ldots \ldots \text{ cm}$. (in $\pi$)