Area of a sector of a circle of radius $36 \, cm$ is $54 \pi \, cm^{2}$. Find the length of the corresponding arc of the sector (in $cm$). (in $\pi$)

If the radius of a circle is doubled,its area becomes $\ldots \ldots \ldots$ times the area of the original circle.

The diameter of a circle with area $38.5 \, m^2$ is $\ldots \ldots \ldots \ldots m$.

If the circumference of a circle and the perimeter of a square are equal,then

Find the area of the segment of a circle of radius $12 \, cm$ whose corresponding sector has a central angle of $60^{\circ}$ (Use $\pi = 3.14$).

The radius of a circular ground is $35 \, m$. Inside it,a $3.5 \, m$ broad road runs around its boundary. $A$ part of the road between two radii forming an angle of measure $72^{\circ}$ at the centre is to be repaired. Find the cost of repairing at the rate of ₹ $80 / m^{2}$. (in ₹)