$A$ 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 $cm$)

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 $cm^2$)

The sides of a triangle are in the ratio of $\frac{1}{2}: \frac{1}{3}: \frac{1}{4}$. If the perimeter is $52 \text{ cm}$,then the length of the smallest side is ........ $\text{cm}$.

In the given figure,$PB$ is one-third of $AB$ and $BQ$ is one-third of $BC.$ If the area of $BPDQ$ is $20 \, cm^{2},$ then what is the area (in $cm^{2}$) of $ABCD$?

$A$ is the centre of a circle whose radius is $8$ and $B$ is the centre of a circle whose diameter is $8$. If these two circles touch externally,then the area of the circle with diameter $AB$ is $.........\pi$.

What will be the area of a circle with circumference equal to $88\, cm$? (in $Sq\, cm$)