If the length and breadth of a rectangular plot are increased by $50 \%$ and $20 \%$ respectively,then how many times will its area be increased?

If a diagonal of a square is doubled,how does the area of the square change?

$A$ wire which when bent in the form of a square encloses an area of $484 \, cm^2$. What will be the enclosed area when the same wire is bent into the form of a circle? (in $cm^2$)

In trapezium $ABCD$,$AB || CD$ and $AB = 2 \, CD$. Its diagonals intersect at $O$. If the area of $\Delta AOB = 84 \, cm^2$,then the area of $\Delta COD$ is equal to (in $cm^2$)

If every side of a triangle is doubled,the area of the new triangle is $K$ times the area of the old one. $K$ is equal to

The length of a rectangular hall is $5\, m$ more than its breadth. The area of the hall is $750\, m^{2}$. The length of the hall is.........$m$