Verbal problem (math)

Question

The surface area of a cube is 45cm^2. What is the volume of the cube?

Answer 1

Hi Axelis!

 

   So the formula for surface area of a cube is 6s^2.  Let's use some Algebra to work backwards.

 

Step one: 6s^2=45 cm^2   Divide both sides by 6 to balance the equation. (this will find the area of one face)

Step two: Find the square root to determine the length of a side.

 

Now that we know s, we can solve for volume. 

 

Volume of a cube is s^3.  Simply take the length you got for s and cube it!

 

Good luck,

Natalie

Answer 2

surface area of a cube is 6 x² = 45 cm²

Therefore, x²= 45/6 

0r x= sqrt (45/6) = sqrt 7.5

 

Volume of the cube = x³= (7,5)^3/2 = 20.539595 cm³