Jawabanmu

2014-09-03T14:25:27+07:00
L.selimut = 2Πrt
3960 = 2 x 22/7 x 21 x t
tinggi = 3960 / 132
tinggi = 30 cm

luas tabung = luas selimut + 2 x luas alas
luas tabung = 3960 + (2 * 22/7 * 21 * 21)
luas tabung = 6732 cm2
2014-09-03T14:30:57+07:00
L = 22/7.21.21 + 3960 + 22/7.21.21
= 1386 + 3960 + 1386
= 6732 cm2