Find the area of the shaded region in $Fig.$ where arcs drawn with centres $A , B , C$ and $D$ intersect in pairs at mid-points $P , Q , R$ and $S$ of the sides $AB , BC,$ $CD$ and $DA ,$ respectively of a square $ABCD$ (Use $\pi=3.14)$ (in $cm ^{2}$)

In $\odot( O , 4), \widehat{ ACB }$ is a minor arc and $m \angle AOB =45 .$ Then, the length of minor $\widehat{ ACB } $ is $\ldots \ldots \ldots \ldots$

As shown in the adjoining diagram, the length of the square plot ABCD is $50 m .$ At each vertex of the plot, a flower bed in the shape of a sector with radius $10 \,m$ is prepared. Find the area of the plot excluding the flower beds. $(\pi=3.14)$ (in $m^2$)

Find the number of revolutions made by a circular wheel of area $1.54\, m ^{2}$ in rolling a distance of $176 \,m .$

The area of a circle is $200\, cm ^{2}$. Then, the area of a minor sector of that circle can be $\ldots \ldots \ldots . . cm ^{2}$.

Will it be true to say that the perimeter of a square circumscribing a circle of radius $a \,cm$ is $8 a \, cm ?$ Give reasons for your answer.