Question

Sas

10. If the surface area of a cube is 390 cm,
then which best describes the length of the
side of the cube?
3 in
in
A. less than 7 cm
B. between 7 cm and 8 cm
C. between 8 cm and 9 cm
D. greater than 9 cm

Answer 1

The length of side of cube ranges between 8cm and 9cm as the given surface area is acquired when length of side of cube is 8.07 cm

Option C is correct.

Explanation:

If the surface area of a cube is 390 cm, then which best describes the length of the side of the cube?

Surface area of cube = 390 cm

The formula used to find surface area of cube is:
`Surface area = 6a^2`

where a is the length of side of cube.

If length of side of cube = 7 cm, the surface area of cube = 294 cm

If length of side of cube = 8 cm, the surface area of cube = 384 cm

Now, if length of side of cube = 8.07 cm (found using calculator, by putting different values in the formula)

We get surface area of cube = 390 cm

So, The length of side of cube ranges between 8cm and 9cm as the given surface area is acquired when length of side of cube is 8.07 cm

Option C is correct.