The area of a sector of a circle of radius $5 \, cm$,formed by an arc of length $3.5 \, cm$,is ..... $cm^2$.

The area of a quadrilateral is $420 \, m^{2}$ and the perpendiculars drawn to one diagonal from the opposite vertices are $18 \, m$ and $12 \, m$. Then,the length of the diagonal is......$m$

The area of a sector of a circle of radius $5 \, cm$,formed by an arc of length $3.5 \, cm$,is (in $cm^2$)

$A$ man runs round a circular field of radius $50\, m$ at the speed of $12\, km/hr$. What is the time taken by the man to take twenty rounds of the field? (in $minutes$)

The largest cone is formed at the base of a cube of side measuring $7 \ cm$. Find the ratio of the volume of the cone to the volume of the cube.

If the circumference of a circle is equal to the perimeter of a square,what is the ratio of the area of the circle to the area of the square?