Jawabanmu

2014-02-03T23:21:59+07:00
Diket: kll = 86
         p - l = 15 -> p = 15 + l
ditanya: l?
jawab:
kll = 2 (p+l)
86 = 2 (15 + l + l)
86 = 2 (15 + 2l) -> 2 x 15 + 2 x 2l
86 = 30 + 4l
86 - 30 = 4l
56 = 4l
56/4 = l
14 = l

p = 15 + l
p = 15 + 14
p = 29

L = p x l
L = 29 x 14
L = 406 cm2