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

$A$ wire is in the form of a circle of radius $42 \ cm$. It is bent into a square. The side of the square is? (in $cm$)

The length and breadth of a rectangular piece of land are in the ratio $5:3$. The owner spent ₹ $6000$ for fencing it from all sides at the rate of ₹ $7.50$ per metre. The difference between its length and breadth is (in metres):

Seven equal cubes each of side $5 \, cm$ are joined end to end. Find the surface area of the resulting cuboid? (in $cm^2$)

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 ........ $m^2$.

If the sides of a rectangle are increased by $20 \%$,the percentage increase in its perimeter is