In a circle,the length of a minor arc is $110 \,cm$ and it subtends an angle of measure $150^{\circ}$ at the centre. Then,the radius of the circle is $\ldots \ldots \ldots \ldots \,cm$.

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 ......... $cm^2$.

In the adjoining diagram, $\overline{ AB }$ and $\overline{ CD }$ are diameters of $\odot( O , 7\, cm )$ perpendicular to each other. $A$ circle is drawn with diameter $\overline{ OD }$. Find the area of the shaded region. (in $cm^2$)

The radius of a circular ground is $35 \, m$. Outside it,a road of width $3.5 \, m$ runs around it. Find the area of the road in $m^2$.

The diagram below is formed by three semicircles. If $OA = OB = 70\, cm,$ find the area of the figure formed (in $cm^2$).

The radius of a field in the shape of a sector is $50 \, m$. The cost of fencing its boundary is ₹ $5400$ at the rate of ₹ $30 / m$. Find the cost of tilling at the rate of ₹ $15 / m^2$. (in ₹)