If the area of a circle is $154\, cm ^{2},$ then its perimeter is (in $cm$)
$44$
$22$
$11$
$55$
In a circle with radius $42\, cm$, a minor arc subtends an angle of measure $60$ at the centre. Find the area of the minor sector and the minor segment corresponding to this arc. $(\sqrt{3}=1.73)$
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 $cm$)
In covering a distance $s$ metres, a circular wheel of radius $r$ metres makes $\frac{s}{2 \pi r}$ revolutions. Is this statement true? Why?
If the radius of a circle is increased by $10 \%,$ then the corresponding area of new circle will be $\ldots \ldots \ldots . . .$
A circular park is surrounded by a road $21\, m$ wide. If the radius of the park is $105\, m ,$ find the area of the road. (in $cm ^{2}$)