In $Fig.$, 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.
False
Given diameter of circle is $d.$
$\therefore$ Diagonal of inner square $=$ Diameter of circle $= d$
Let side of inner square $EFGH$ be $x.$
$\therefore$ In right angled $\triangle EFG$
$E G^{2}=E F^{2}+F G^{2} \quad$ [by Pythagoras theorem]
$\Rightarrow d^{2}=x^{2}+x^{2}$
$\Rightarrow d^{2}=2 x^{2} \Rightarrow x^{2}=\frac{d^{2}}{2}$
But side of the outer square $ABCS$ $=$ Diameter of circle $= d$
$\therefore \quad$ Area of outer square $= d ^{2}$
Hence, area of outer square is not equal to four times the area of the inner square.
Four circular cardboard pieces of radii $7\, cm$ are placed on a paper in such a way that each piece touches other two pieces. Find the area of the portion enclosed between these pieces. (in $cm^2$)
In $Fig.$ a circle of radius $7.5 \,cm$ is inscribed in a square. Find the area of the shaded region (Use $\pi=3.14$ ) (in $cm^2$)
In $\odot( O ,\, 5.6), \overline{ OA }$ and $\overline{ OB }$ are radii perpendicular to each other. Then, the difference of the area of the minor sector formed by minor $\widehat{ AB }$ and the corresponding minor segment is $\ldots \ldots \ldots \ldots cm ^{2}$.
In $\odot( O , r) \overline{ OA }$ and $ \overline{ OB }$ are two radii perpendicular to each other. If the, perimeter of the minor sector formed by those radii is $20\,cm ,$ then $r=\ldots \ldots \ldots . . . cm$
In a circle with radius $42\,cm ,$ an arc subtends an angle of measure $120$ at the centre. Then, the area of the minor sector formed by that arc is $\ldots \ldots \ldots . . cm ^{2}$.