The cost of erecting wall all around a circular ground at the rate of ₹ $60 / m$ comes to be ₹ $26.400 .$ Find the cost of levelling the ground at the rate of ₹ $50 / m ^{2}$. (in ₹)
In a circle with radius $r$, the area of a sector formed by an arc of length $l$ is.........
From a circular metallic sheet with radius $21\, cm ,$ a regular hexagon of side $21\, cm$ is cut off. Find the area of the remaining sheet. $(\sqrt{3}=1.73)$ (in $cm^2$)
In a circle with radius $14 \,cm$, an arc subtends a right angle at the centre. Find the length of this arc and the area of minor sector and minor segment formed by it.
Find the diameter of the circle whose area is equal to the sum of the areas of the two circles of diameters $20\, cm$ and $48 \,cm .$ (in $cm$)