What is the volume of the cube if the diagonal is 1?

Expert Answers
hala718 eNotes educator| Certified Educator

To find the volume of the cube we need to find the length of the side.

Given the diagonal of the cube is 1.

Let the side of the cube be x.

Then we know that the diagonal is given by:

d = sqrt(3x^2) = (sqrt3)*x

==> 1= sqrt3*x

==> x=  1/ sqrt3

==> x= sqrt3/3

Now we will calculate the volume of the cube.

We know that the volume of the cube = x^3

==> V = (sqrt3/3)^3 = 3sqrt3/ 27 = sqrt3/9

Then, the volume of the cube is sqrt3/ 9 cubic units.

justaguide eNotes educator| Certified Educator

The diagonal of a cube is given as sqrt (3L^2), where L is the length of the side.

We know that the diagonal is 1.

=> 1 = sqrt (3L^2)

=> 1^2 = 3L^2

=> L^2 = 1/3

=> L = sqrt( 1/3)

The volume of a cube is L^3

=> [sqrt (1/3)]^3

=> (1/3) sqrt (1/3)

The required volume of the cube is (1/3)*sqrt (1/3).

neela | Student

A cube is a regular prism which has  a square top, bottom and lateral surfaces with equal length, width and height.

If the side of the cube is x, then its diagonal d is given by:

d = x^2+x^2+x^2 = 3x^2.

So , if diagonal d= 1, then 1= 3x^2 => x= sqrt(1/3) is the side of the cube.

So the volume of the cube = x^3 = (sqrt(1/3)}^3 = (1/3^3/2)= 1/sqrt27 = 0.19245 cubic units.