In a circle with radius $6\, cm ,$ a minor are subtends an angle of measure $60$ at the centre. Find the area of the minor sector and the major sector corresponding to that arc.
Here, the radius of the circle $r=6 cm$ and the measure of the angle subtended at the centre $\theta=60$.
Area of a minor sector $=\frac{\pi r^{2} \theta}{360}$
$=\frac{22}{7} \times \frac{6 \times 6 \times 60}{360}$
$=\frac{132}{7} cm ^{2}$
Area of a major sector
$=$ Area of the circle-Area of the minor sector
Area of a major sector
= Area of the circle-Area of the minor sector
$=\pi r^{2}-\frac{\pi r^{2} \theta}{360}$
$=\pi r^{2}\left(1-\frac{\theta}{360}\right)$
$=\frac{22}{7} \times 6 \times 6\left(1-\frac{60}{360}\right)$
$=\frac{22}{7} \times 6 \times 6 \times \frac{5}{6}$
$=\frac{660}{7} cm ^{2}$
Thus, the area of the minor sector is $\frac{132}{7} cm ^{2}$
and the area of the major sector is $\frac{660}{7-2} cm ^{2}$.
Find the radius of a circle whose circumference is equal to the sum of the circumferences of two circles of radii $15 \,cm$ and $18 \,cm$ (in $cm$)
If the radius of a circle is doubled, its area becomes $\ldots \ldots \ldots .$ times the area of the original circle.
The diameter of a circular garden is $210 \,m .$ Inside it, all along the boundary, there is a path of uniform width $7 \,m .$ Then, the area of the path is $\ldots \ldots \ldots \ldots m ^{2}$.
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