Jawabanmu

2013-12-06T10:51:13+07:00
320 cm2
panjang 20cm lebar 16cm
jadi luasnya 20 x 16 =320 cm2
Jawaban paling cerdas!
2013-12-06T12:17:06+07:00
K= 72 cm
p = 4+x
l = x

K = 2 (p + l)
   = 2 (4+x + x)
   = 2 (4 + 2x)
   = 8 + 4x
72 = 8 + 4x
72 - 8 = 4x
64 / 4 = x
16 = x

L = p x l
  = (4+16) x 16
  = 20 x 16
  = 320 cm2
1 5 1