The diagram below is formed by three semicircles. If $OA = OB =70\, cm ,$ find the area of the figure formed. (in $cm^2$)
$11586$
$11550$
$12051$
$17361$
The length of the minute hand of a clock is $7\,cm$. The area of the region swept by it in $20$ minutes is $\ldots \ldots \ldots . cm ^{2}$.
If the perimeter of a circle is equal to that of a square, then the ratio of their areas is
The ratio of the areas of the circles with radii $8\,cm$ and $12 \,cm$ is $\ldots \ldots \ldots \ldots .$
The length of the minute hand of a clock is $5\, cm$. Find the area swept by the minute hand during the time period $6: 05$ $a.m.$ and $6: 40$ $a.m.$ (in $cm^2$)
In $Fig.$, a square is inscribed in a circle of diameter $d$ and another square is circumscribing the circle. Is the area of the outer square four times the area of the inner square? Give reasons for your answer.