Jawabanmu

2014-05-31T09:37:15+07:00
Lp = 2(pl + pt + lt)
426 = 2(108 + 12t + 9t)
213 = 108 + 21t
t = 5
2014-05-31T09:44:08+07:00
Luas : 426 cm
Panjang:12 cm
Lebar : 9 cm
12x.9x = 426cm
108x    = 426cm
   x      =3,944