Jawabanmu

2014-05-16T19:32:48+07:00
Diketahui p : l : t = 4x : 3x : 2x
diket l= 12 cm,
l-> 3x = 12
x = 4 cm

jadi panjang = 4x = 4.4 = 16 cm
tinggi = 2x = 2.4 =8 cm

Lperm = 2 (pl) = 2(pt) + 2 (lt)
=2(16.12) +  2(16.8) + 2 (12.8)
=2 (192)  + 2(128) + 2 (96)
=384 + 256 + 192
=832 cm2
Jawaban paling cerdas!
2014-05-16T20:11:50+07:00
3:12=4 jadi 
panjang 4*4=16
Lebar 12 
Tinggi 2*4=8

L    =   2 {( p . l ) + ( l . t ) + ( p . t )}
      =   2 {(16.12) + (12.8) + (16.8)}
      =   2 . (192+96+128)
      =   2 . 416
      =   832