If the radius of a circle is increased by $10 \%,$ its area will increase by $\ldots \ldots \ldots . \%$

In $\odot(O, r)$,minor $\widehat{ACB}$ subtends an angle of measure $72^{\circ}$ at the centre. Then,the ratio of the length of minor $\widehat{ACB}$ and the circumference of the circle is ............

In the figure,a square of diagonal $8\, cm$ is inscribed in a circle. Find the area of the shaded region.

The length of a square field is $50 \, m$. $A$ cow is tethered at one of the vertices by a $3 \, m$ long rope. Find the area of the region of the field in which the cow can graze. $(\pi = 3.14)$ (in $m^2$)

$\overline{ OA }$ and $\overline{ OB }$ are radii of a circle perpendicular to each other. If $OA = 5.6 \, cm$,then the area of the minor sector formed by those radii is .......... $cm^2$.

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