Jawabanmu

2014-08-29T14:39:15+07:00
R = 6,5 cm
t = 18 cm

L = 2 π r (r + t)
   = 2 . 3,14 . 6,5 (6,5 + 18)
   = 40,82 . 24,5
   = 1000,09 cm²
2014-08-29T18:32:41+07:00
Lt = 2 π r (r + t)
= 2 x 3,14 x 6,5 (6,5 + 18)
= 40,82 x 24,5
= 1000,09 cm²