Calculating the length of an edge of a cube - GMAT Quantitative

To find the surface area of a cube, use the following formula:

Where s is our side length.

Rearrange for s to get the following:

Plug in 54 for SA and solve

Don't forget your units, in this case centimeters so we get 3 centimeters

To solve for the side length of the cube, we need to use the formula for surface area. There are six faces on a cube, so its total surface area is just six times the area of one of its square faces, which is given by the side length squared:

Volume of a cube is equal to the cube of its side. 343 is equal to 7 cubed, so the length of the whole cube is 7 cm. The cube is made up of 27 smaller cubes though. That means that one face of the cube is made up of 9 cubes and one edge of the whole cube is made up of 3 small cubes. That means that the length of one small cube is equal to the total length of one side divided by the numbers of cubes per side

Then we get our final answer by doing:

We are given the length of the diagonal of the cube.

Therefore we can find the length of an edge by using the formula

or , and .

Therefore, the final answer is .

To find side length, you must use the equation for volume of a cube and solve for .

Thus,

We solve for the side of the cube by deriving it from the volume of a cube formula:

To find the surface area of a cube, use the following formula:

Where s is our side length.

Rearrange for s to get the following:

Plug in 54 for SA and solve

Don't forget your units, in this case centimeters so we get 3 centimeters

To solve for the side length of the cube, we need to use the formula for surface area. There are six faces on a cube, so its total surface area is just six times the area of one of its square faces, which is given by the side length squared:

Volume of a cube is equal to the cube of its side. 343 is equal to 7 cubed, so the length of the whole cube is 7 cm. The cube is made up of 27 smaller cubes though. That means that one face of the cube is made up of 9 cubes and one edge of the whole cube is made up of 3 small cubes. That means that the length of one small cube is equal to the total length of one side divided by the numbers of cubes per side

Then we get our final answer by doing:

We are given the length of the diagonal of the cube.

Therefore we can find the length of an edge by using the formula

or , and .

Therefore, the final answer is .

To find side length, you must use the equation for volume of a cube and solve for .

Thus,

We solve for the side of the cube by deriving it from the volume of a cube formula:

To find the surface area of a cube, use the following formula:

Where s is our side length.

Rearrange for s to get the following:

Plug in 54 for SA and solve

Don't forget your units, in this case centimeters so we get 3 centimeters

To solve for the side length of the cube, we need to use the formula for surface area. There are six faces on a cube, so its total surface area is just six times the area of one of its square faces, which is given by the side length squared:

Volume of a cube is equal to the cube of its side. 343 is equal to 7 cubed, so the length of the whole cube is 7 cm. The cube is made up of 27 smaller cubes though. That means that one face of the cube is made up of 9 cubes and one edge of the whole cube is made up of 3 small cubes. That means that the length of one small cube is equal to the total length of one side divided by the numbers of cubes per side

Then we get our final answer by doing:

We are given the length of the diagonal of the cube.

Therefore we can find the length of an edge by using the formula

or , and .

Therefore, the final answer is .

To find side length, you must use the equation for volume of a cube and solve for .

Thus,

To find side length, you must use the equation for volume of a cube and solve for .

Thus,

We solve for the side of the cube by deriving it from the volume of a cube formula: