Plz Help

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Formula  for arc length

Arc length  =  r * (theta in radians)    

So we  have that

18 . 4   = r  *  (13pi  /18)        multiply both sides by  (18/  [ 13 pi])

18.4 *  18 / [13pi ]     =  r  ≈  8.1  inches

13pi/18 * 180/pi = 13 * 180 / 18 = 130°        

Arc  L = 18.4 in

r = { [ (360° * 18.4) /130° ] / pi} / 2 

No it is right on cphill answer