If the space diagonal of cube C is 5 inches long, what is the length, in inches, of the diagonal of the base of cube C?
Choose the correct choice:
A) 5/(√6)
B) 5·√(2/3)
C) 5·√(3/2)
D) 5·√3
E) 5·√6
n cube C, let's say that each side has side length x   So, the diagonal = √(x² + x² + x²) = √(3x²)   Here, we're told that the diagonal has length 5, so we can write:   5 = √(3x²)   Square both sides to get: 25 = 3x²   Divide both sides by 3 to get: 25/3 = x²   Square root both sides: √(25/3) = x   Or.... (√25)/(√3) = x   Simplify: 5/(√3) = x   ANSWER:5·√(2/3)
<result>B</result>
If the space diagonal of cube C is 5 inches long, what is the length, in inches, of the diagonal of the base of cube C?