In a circle with radius $r,$ an arc subtends an angle of measure $\theta$ at the centre. Then, the area of major sector is $=$ ..........
$\frac{\pi r \theta}{180}$
$2 \pi r-\frac{\pi r \theta}{180}$
$\pi r^{2}-\frac{\pi r^{2} \theta}{360}$
$\frac{\pi r^{2} \theta}{360}$
If the sum of the areas of two circles with radii $R_{1}$ and $R_{2}$ is equal to the area of a circle of radius $R$, then
The radius of a circular ground is $35 \,m$. Outside it, runs a road of width $3.5\, m$. Find the area of the road. (in $m^2$)
$\widehat{ ACB }$ is a minor arc of $\odot( O , 8 \,cm ) .$ If $m \angle AOB =45,$ the length of minor $\widehat{ ACB }$ is $\ldots \ldots \ldots . . cm .$
Find the circumference and the area of a circular ground with radius $77\, m$.
Find the area of a sector of a circle of radius $28 \,cm$ and central angle $45^{\circ} .$ (in $cm ^{2}$)