The ratio of radii of two circles is $4: 5.$ Then, the ratio of their areas is...........
$4: 5$
$16: 25$
$25: 16$
$5: 4$
The length of the minute hand of a clock is $10.5\, cm .$ Find the area of the region swept by it between $2.25 \,PM$ and $2.40 \,PM$. (in $cm^2$)
If the radius of a circle is doubled, its area becomes $\ldots \ldots \ldots .$ times the area of the original circle.
The length of a square field is $50\, m .$ A cow is tethered at one of the vertices by a $3\, m$ long rope. Find the area of the region of the field in which the cow can graze. $(\pi=3.14)$ (in $m^2$)
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.
If the length of an arc of a circle of radius $r$ is equal to that of an arc of a circle of radius $2 r$, then the angle of the corresponding sector of the first circle is double the angle of the corresponding sector of the other circle. Is this statement false? Why?