Jawabanmu

2014-02-11T20:14:37+07:00
Jawaban paling cerdas!
2014-02-11T20:18:25+07:00
P = panjang
l = lebar
: = bagi
/ = per
. =  kali

p = 3/2 l

k = 2 . (p + l)
40 : 2 = 3/2 l + l
20 = 3/2 l + 2/2 l
20 = 5/2 l
l = 2/5 . 20
l = 8

p = 3/2 . l
p = 3/2 . 8
p = 12