Jawabanmu

2014-05-28T20:26:46+07:00
Lp kubus = 6 x 21^2
= 6 . 441
=2646 cm^2
2014-05-28T20:31:07+07:00
Rusuk kubus = 21 cm Lpermukaan kubus =6 x s^2 Lp = 6 x (21 x 21) Lp = 6 x 441 Lp = 2646 cm^2 (Maaf jika salah)