What is the volume of a rectangular parallelepiped if the areas of its three faces are 6.12.8 cm2?
The volume of a rectangular parallelepiped is calculated by the formula:
V = abc, where abc are sides.
Knowing that the areas of its faces are equal to S1 = 6 cm2, S2 = 12 cm2, S3 = 8 cm2, we can calculate what the sides of a rectangular parallelepiped are equal to.
Knowing the area formula for a rectangle S = ab, we find the sides:
a * b = 6 cm2.
b * c = 12 cm2.
a * c = 8 cm2.
Side a = 6: b; side c = 12: b; side b = (6: b) * (12: b) = 8.
Let’s expand the brackets by multiplying each factor of the first parenthesis by each factor of the second:
6 * 12: b * b = 8.
72: b2 = 8.
b ^ 2 = 72: 8.
b ^ 2 = 9.
b = √9.
b = 3.
Let’s find the rest of the sides:
a * b = 6 => a * 3 = 6 => a = 2.
b * c = 12 => 3 * c = 12 => c = 4.
It turns out that the volume of a rectangular parallelogram is:
V = abc = 2 * 3 * 4 = 24 cm3.