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 from the following
A) 5 / ( √ 6 )
B) 5 · √ ( 2 / 3 )
C) 5 · √ ( 3 / 2 )
D) 5 · √ 3
E) 5 · √ 6

Rationale: n cube c , let ' s say that each side has side length x so , the diagonal = √ ( x ² + x ² + x ² ) = √ ( 3 x ² ) here , we ' re told that the diagonal has length 5 , so we can write : 5 = √ ( 3 x ² ) square both sides to get : 25 = 3 x ² divide both sides by 3 to get : 25 / 3 = x ² square root both sides : √ ( 25 / 3 ) = x or . . . . ( √ 25 ) / ( √ 3 ) = x simplify : 5 / ( √ 3 ) = x answer : b
Answer: B