<PRE><B>Question 234302</B>
Use the formula:

Surface Area of a Cube = 6 a^2 

The diagonal is the hypotenuse of a right triangle in the cube.

The legs are represented by the letter a.

a^2 + a^2 = 4^2

2a^2 = 16

a^2 = 16/2

a^2 = 8

sqrt{a^2} = sqrt{8}

a = 2(sqrt{2})

Now that we know the value of a, plug it into the formula for the surface area of a cube.

Surface Area of a Cube = 6 (2(sqrt{2})^2 

Can you finish now?

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