The area of a circle is $38.5\, m^2$,then its circumference will be $\ldots \ldots \ldots \ldots \, m$.

Find the circumference and the area of a circle with diameter $42 \, cm$.

The side length of square $ABCD$ shown in the diagram is $42 \ cm$. The shaded design is formed by drawing semicircles on all the sides of the square. Find the area of the shaded design in $cm^2$.

In $\odot(O, r)$,the length of minor $\widehat{ACB}$ is $\frac{1}{6}$ times the circumference of the circle. Then,the measure of the angle subtended at the centre by minor $\widehat{ACB}$ is ......... (in $^{\circ}$)

Find the difference of the areas of a sector of angle $120^{\circ}$ and its corresponding major sector of a circle of radius $21 \, cm$. (in $cm^2$)

Find the area of the shaded design in the figure where $ABCD$ is a square of side $10 \, cm$ and semicircles are drawn with each side of the square as diameter. (in $cm^2$) (Use $\pi = 3.14$)