From a circle, a sector with a central angle of 30° is cut off. If the length of the arc of this sector is 5.5 cm, then find the radius (in cm) of the circle. { use pi = 22/7}
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Correct answer: C
Explanation
The correct answer is option 3 i.e. 10.5
Central angle (θ) = 30°
Length of the arc (l) = 5.5 cm
Length of arc (l) = θ/360 × 2πr where r = radius of the circle
So, 5.5 = (30/360) × 2 × (22/7) × r
⇒ 5.5 = (11/21) × r
⇒ r = 5.5 × (21/11) = 10.5
Therefore, the radius of the circle is 10.5 cm.