The area of a circular playground is $22176\, m ^{2}$. Find the cost of fencing this ground at the rate of $Rs.\, 50$ per $metre.$ (in $Rs.$)
$26000$
$28400$
$29400$
$26400$
Find the area of a sector of circle of radius $21\, cm$ and central angle $120^{\circ}$. (in $cm ^{2}$)
The maximum area of a triangle inscribed in a semicircle having radius $10\,cm$ is $\ldots \ldots \ldots . . cm ^{2} .$
The length of the minute hand of a clock is $10.5 \,cm .$ The area of the region swept by it in $20$ minutes is $\ldots \ldots \ldots . . cm ^{2}$.
In a circle with radius $r$, the area of a sector formed by an arc of length $l$ is.........
The length of a minor arc of a circle is given by the formula $\ldots \ldots \ldots \ldots$