Jawabanmu

2014-04-29T21:36:29+07:00
Volum kubus = S x S x S
512 = S³
S = ∛512 = 8

V balok = P x L x T
512 = ( \frac{1}{2} S) . L . (2L)
512 = 4 . 2 L²
2L² = 512 : 4
2L² = 128
L² = 64
L = 8

T = 2L
T = 16

Lp =2( (PxL)+(LxT)+(PxT) )
Lp = 2 ( (4x8)+(8x16)+(4x16) )
Lp = 2 ( (32)+(128)+(64) )
Lp = 2 (224)
Lp = 448