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Question
The measure of an arc of a circle is 80° and its radius is 18 cm. Find the length of the arc. (π = 3.14)
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Solution
Radius of the arc (r) = 18 cm
Measure of the arc (θ) = 80º
Length of an arc (l) = `θ/360` × 2πr
∴ Length of an arc (l) = `80/360` × 2 × 3.14 × 18
∴ Length of an arc (l) = `80/360` × 36 × 3.14
∴ Length of an arc (l) = 8 × 3.14
∴ Length of an arc (l) = 25.12
Thus, the length of the arc is 25.12 cm.
Notes
There is printing mistake in textbook.
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