The radius of a wheel is $0.25\, m$. The number of revolutions it will make to travel a distance of $11\, km$ will be

$A$ figure consists of a square of side '$a$' $m$ with semi-circles drawn on the outside of the square. The area (in $m^{2}$) of the figure so formed will be

$A$ circular road runs around a circular garden. If the difference between the circumference of the outer circle and the inner circle is $44\, m$,then find the width of the road in $m$.

The height of an equilateral triangle whose perimeter is $24 \, cm$ is

$ABCD$ is a trapezium in which $AB \parallel CD$ and $AB = 2CD$. If its diagonals intersect each other at $O$,the ratio of the area of triangle $AOB$ and $COD$ is

The ratio of the area of a sector of a circle to the area of the circle is $1:4$. If the area of the circle is $154 \, cm^2$,the perimeter of the sector is ........ $cm$.