The diameter of a circle with area $154\,cm^{2}$ is $\ldots \ldots \ldots . cm$.

Find the difference of the areas of two segments of a circle formed by a chord of length $5 \, cm$ subtending an angle of $90^{\circ}$ at the centre.

The radius of a circle is $12 \, cm$. Find its circumference and area $(\pi = 3.14)$.

The area of a square inscribed in a circle with radius $70 \, cm$ is $\ldots \ldots \ldots \, cm^2$.

As shown in the diagram,rectangle $ABCD$ is inscribed in a circle. If $AB = 8 \, cm$ and $BC = 6 \, cm$,find the area of the shaded region in the diagram. $(\pi = 3.14)$ (in $cm^2$)

In $\odot(O, r)$,minor arc $\widehat{ABC}$ subtends a right angle at the centre. The area of the minor segment formed by $\widehat{ABC}$ is $14.25\,cm^2$ and the area of $\Delta OAC$ is $25\,cm^2$. Then,the area of the minor sector formed by $\widehat{ABC}$ is $\ldots \ldots \ldots cm^2$.