The angle subtended by an arc at the center is 72°, and its length is 22 cm. Find the radius of the circle.
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Correct answer: A
Explanation
Given:
Central angle (θ) = 72°
Arc length (L) = 22 cm
Formula:
Arc length (L) = (θ/360) × 2πr
22 = (72/360) × 2πr
22 = (1/5) × 2πr
22 = (2πr) / 5
110 = 2πr
r = 110 / (2π)
r = 17.5 cm