Jawabanmu

2014-04-08T11:28:29+07:00
Luas permukaan balok = (2 x p xl) + (2 x p x t) + (2 x l x t)
(2 x 4 x 5) + (2 x 4 x 6) + ( 2 x 5 x 6 ) = 40 + 48 + 60 = 58 + 60 = 118 cm2
2014-04-08T11:34:03+07:00
Lp = 2 (pl + pt + lt)
     =  2 (4.5 + 4.6 + 5.6)
     = 2 (20+24+70)
     = 2.74
     = 148