A circular pond is of diameter $17.5 \mathrm{m}$. It is surrounded by  $2 \mathrm{m}$ wide path .Find the cost of constructing the path at the rate of $₹25$ per square metre. $($Use $\mathrm{\pi }=3.14)$

A road which is $7 \mathrm{m}$ wide surrounds a circular park whose circumference is $352 \mathrm{m}$. Find the area of the road.

Prove that the area of a circular path of uniform width $\mathrm{h}$ surrounding a circular region $\mathrm{r}$ is $\mathrm{\pi h} (2\mathrm{r}+\mathrm{h})$.

Find, in terms of $\mathrm{\pi }$, the length of the arc that subtends an angle of $30°$ at the centre of a circle of radius $4 \mathrm{cm}$.

Find the angle subtended at the centre of a circle of radius $5 \mathrm{cm}$ by an arc of length $(5\mathrm{\pi }/3) \mathrm{cm}$.