In a circle of radius 21 cm, an arc subtends an angle of $60^o$ at the centre. Find area of the sector formed by the arc.

AcademicMathematicsNCERTClass 10

Given:

Radius of the circle $r=21 \mathrm{~cm}$.

Angle subtended by the arc $=60^{\circ}$

To do:

We have to find the area of the sector.

Solution:

We know that,

Area of the sector $=\pi r^{2} \times \frac{\theta}{360^{\circ}}$

Therefore,

Area of the sector formed by the arc$=\frac{22}{7}(21)^{2} \times \frac{60^{\circ}}{360^{\circ}}$

$=\frac{22}{7} \times 21 \times 21 \times \frac{1}{6}$

$=231 \mathrm{~cm}^{2}$

The area of the sector is $231 \mathrm{~cm}^{2}$.  

raja
Updated on 10-Oct-2022 13:23:55

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