$A$ cow is tied by a rope at the corner of a rectangular field. If the length of the rope is $14\, m$,then the area of the field which the cow could graze is.......$m^2$

In a quadrilateral $ABCD$,the sides $AB, BC, CD, DA$ measure $20\, m, 13\, m, 17\, m$ and $10\, m$ respectively,and the diagonal $AC$ is $21\, m$. The area of the quadrilateral is ........ $m^2$.

Each edge of a cube is increased by $50 \%$. Then,the percentage increase in its surface area is (in $\%$)?

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 ........ $cm$.

Find the length of a rope by which a cow must be tethered in order that it may be able to graze an area of $9856 \, m^{2}$. (in $m$)

The number of marble slabs of size $20\, cm \times 30\, cm$ required to pave the floor of a square room of side $3\, m$ is: