volume balok yang mempunyai luas sisi masing ²150cm²,120cm²,dan 80cm²adalah

p×l = 150 → l = 150/p
p×t = 120 → t = 120/p
l×t = 80
150/p × 120/p = 80
18000/p² = 80
p² = 18000/80 = 225
p = √225 = 15 cm
l = 150/p = 150/15 = 10 cm
t = 120/p = 120/15 = 8 cm

volume = p×l×t
= 15 × 10 × 8 = 1200 cm³