$A$ circular park is surrounded by a road $21\, m$ wide. If the radius of the park is $105\, m$,find the area of the road in $m^2$.

In a circle with radius $21 \, cm$,the length of a minor arc is $33 \, cm$. Find the measure of the angle subtended at the centre by this arc. Also,find the area of the minor sector and the area of the minor segment formed by it.

Find the area of the shaded region in the figure,where a circular arc of radius $6 \, cm$ has been drawn with vertex $O$ of an equilateral triangle $OAB$ of side $12 \, cm$ as centre. $\left[ \text{Use } \pi = \frac{22}{7} \right]$

Find the area of the shaded region in the figure,if the radii of the two concentric circles with center $O$ are $7\, cm$ and $14\, cm$ respectively and $\angle AOC = 40^{\circ}$. [Use $\pi = \frac{22}{7}$]

Find the area of the shaded region given in the figure.

In $\odot(O, 6)$, $\widehat{ABC}$ is a major arc and $m \angle AOC = 60^{\circ}$. Then, the length of major $\widehat{ABC}$ is ........... (in $\pi$)