Jawabanmu

2014-01-05T19:37:31+07:00
Kel = 2 x (p+l)
36 cm= 2x ( [l+4cm] + l) => p = l+4 krn panjang= lebar lebih 4 cm 
36 cm = 2 x (2l + 4cm)
36 cm / 2 = 2l+4 cm
18 cm = 2l+4cm
18cm-4cm = 2 x lebar
14 cm = 2 lebar 
lebar = 14: 2 = 7 cm, panjang = 11 cm
Luas = p x l
=(11x7) cm
= 77 cm
2014-01-05T19:42:53+07:00
Diket : p = l + 4
K = 2 (p + l)
36 = 2 ( l + 4 + l)
36 = 4l + 8
4l = 36 - 8
4l = 28
  l = 28 / 4
    = 7

p = l + 4
   = 7 + 4
   = 11

luas = p x l
       = 7 x 11
       = 77