Find the area of a sector of a circle of radius $21\text{ cm}$ with central angle $60^\circ$.
Step-by-Step Solution
Key Concept: $\text{Area} = \dfrac{60}{360} \times \dfrac{22}{7} \times 21^2 = \dfrac{1}{6} \times 1386 = 231\text{ cm}^2$.
$\text{Area} = \dfrac{1}{6} \times \dfrac{22}{7} \times 441 = \dfrac{1}{6} \times 1386$. [1.0 Mark]
$= 231\text{ cm}^2$. [1.0 Mark]
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🎯 Official CBSE Marking Scheme:
Applying sector area formula: 1.0 Mark
Evaluating area $= 231\text{ cm}^2$: 1.0 Mark
Correct Answer: