Question 1014342
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The area of the circle is 81pi sq. cm. Find the arc length of this circle that subtends a central angle of pi/3.
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1. To find the radius, use this equation

   S = {{{pi*r^2}}},   or
   
   {{{81*pi}}} = {{{pi*r^2}}}.

   Then you immediately get r = 9 m.


2. The arc length is 

   L = {{{r*alpha}}} = {{{9*(pi/3)}}} = {{{9*(3.14/3)}}} = {{{3*3.14}}} m.

   Calculate yourself 3*3.14.
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