Question

a. Find the length of a 20degrees° arc of a circle whose radius is 7 cm.

b. Explain why the arc length in part ​(a) is longer or shorter in centimeters if the radius had been 12 cm.

c. Find the arc length when the radius is increased to 12 cm.

Answer 1

We know that

a) In this case, r = 7 cm and

   Therefore,

  

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b) Since arc length is directly proportional to the radius of the cicle, therefore, arc length is longer if the radius had been 12 cm

c) In this case, r = 12 cm and

   Therefore,

  

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