rusuk balok yang bertemu pada pojok balok berbanding 5:3:1. jika volume balok 10935cm³ tentukanlah luas balok tersebut

P = 5X
L = 3X
T = X
V = 10935 cm³

V = P . L . T
10935 cm³ = 5X . 3X . X
10935 cm³ = 15 X³
X³ = 10935 cm³ / 15
X³ = 729 cm³
X = 9 cm

* SUBTITUSI X = 9 cm
P = 5X
= 5 . 9 cm
= 45 cm

L = 3X
= 3 . 9 cm
= 27 cm

T = X
= 9 cm

LP = 2 pt + 2 pl + 2lt
LP = 2 ( pt + pl + lt )
LP = 2 ( 45 . 9 + 45 . 27 + 27 . 9 )
LP = 2 ( 405 + 1215 + 243 )
LP = 2 ( 1863 cm²)
LP = 3726 cm²

Volume = 10935
5x.3x.x = 10935
15x³ = 10935
x³ = 10935÷15
x³ = 729
x = 9 cm

Panjang = 5x = 5.9 = 45 cm
Lebar = 3x = 3.9 = 27 cm
Tinggi = x = 9 cm

Luas permukaan
= 2(pl+pt+lt)
= 2(45.27+45.9+27.9)
= 2(1215+405+243)
= 2(1863)
= 3726 cm²