Jawabanmu

2014-02-03T20:13:39+07:00
Pi r² = 2464
r² = 2464 . 7 / 22
   = 112 . 7 
   = 16 x 49
r = √16 x 49
  = 4 x 7 = 28 cm
d = 56 cm

k = 2 π r 
   = 2 . 22/7 . 28
   = 44 . 4 
   = 176 cm
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