Sebuah balok memiliki luas alas 48 cm², luas sisi samping 30 cm², dan luas sisi depan 40 cm². Volume balok itu adalah

volume balok = p × l × t
luas alas = p × l => 48 = p × l => p = 48/l
luas samping = l × t => 30 = l × t => t = 30/l

luas depan = p × t => 40 = 48/l × 30/l => 1440/l^2 (^ artinya pangkat) => 40 × l^2 = 1440 => l^2 = 1440/40 => l^2 = 36 => l = 6

luas alas = p × l => 48 = p × 6 => p = 48/6 => p = 8

luas samping = l × t => 30 = 6 × t => t = 30/6 => t = 5

jadi volume balok = p × l × t = 8 × 6 × 5 = 240 cm^3