In the figure, a circle of radius $7.5 \, cm$ is inscribed in a square. Find the area of the shaded region (Use $\pi = 3.14$) (in $cm^2$).

Find the area of the flower bed (with semi-circular ends) shown in the figure.

The diameters of front and rear wheels of a tractor are $80 \,cm$ and $2 \,m$ respectively. Find the number of revolutions that the rear wheel will make in covering a distance in which the front wheel makes $1400$ revolutions.

The circumference of a circle with radius $8.4\,cm$ is $\ldots \ldots \ldots \ldots cm$.

Is it true that the distance travelled by a circular wheel of diameter $d \text{ cm}$ in one revolution is $2 \pi d \text{ cm}$? Why?

In the figure,a square is inscribed in a circle of diameter $d$ and another square is circumscribing the circle. Is the area of the outer square four times the area of the inner square? Give reasons for your answer.