Jawabanmu

2014-03-25T17:58:14+07:00
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
2014-03-25T19:56:17+07:00
P=3/5x(40/2)=3/5x20=12cm L=2/5x(40/2)=2/5x20=8cm