Jawabanmu

2014-05-30T15:48:02+07:00
P:t = 2:1
t=9
p=2.t
p=18

Lp = 2pl + 2lt +2pt
1080 = (2.18.l) + (2.l.9) + (2.18.9)
1080 = 36l + 18l + 324
1080 = 54l + 324
1080 - 324 = 54l
756 = 54l
 \frac{756}{54} = l
14 = l

V = p.l.t
V = 18.14.9
V = 2268 cm³
2014-05-30T15:50:34+07:00
Luas permukaan = 2 (pl + pt + lt)
1080  cm^{2} = 2 {(18xl)+(18x9)+(lx9)}
540  cm^{2} = 18l + 162 + 9l
540 - 162 = 17l
378 = 17l
l = 378 : 17
l = 14 cm

V = p x l x t
V = 18 x 9 x 14
V = 2268  cm^{3}