Question

Perbandingan pnjng, lbr,dn tinggi dgn prbandingan 5:3:2. jika balok itu memepunyai luas permukaan 248cm2 . maka volumenya adlah

Answer 1

P : l : t = 5 : 3 : 2

p = 5x

l = 3x

t = 2x

Lp = 2(p . l) + 2(p . t) + 2(l . t)
248 = 2(5x . 3x) + 2(5x . 2x) + 2(3x . 2x)
248 = 2(15x^2) + 2(10x^2) + 2(6x^2)
248 = 30x^2 + 20x^2 + 12x^2
248 = 62x^2
4 = x^2
2 = x

p = 5x
p = 5 . 2
p = 10 cm

l = 3x
l = 3 . 2
l = 6 cm

t = 2x
t = 2 . 2
t = 4 cm

V = p . l . t
V = 10 . 6 . 4
V = 240 cm^3