The side length of a cube is √7 cm.

which answer is a rational value?

the volume.

the perimeter of the front square.

the diagonal of the back square.

the total area of the top and bottom squares.

The answer is The total area of the top and bottom squares. s = √7 cm is irrational value and we need rational value. Let's check all choices: A. The volume. V = (s)^3. If s = √7, V = (√7)^3 = 7√7 - irrational value. B. The perimeter of the front square. P = 4 * s = 4 * √7 = 4√7 - irrational value. C. The diagonal of the back square. d = s√2 = √7 * √2 = √(7*2) = √14 - irrational value. D. The total area of the top and bottom squares. A = 2 * s^2 = 2 * (√7)^2 = 2 * 7 = 14 - rational value.

24 is the correct answer.