What is the measure of the angle X made by the diagonals of the any adjacent sides of a cube.  Answers
A) 30	B) 45	C) 60	D) 75	E) 90

Rationale: "c . . 60 degrees all the diagonals are equal . if we take 3 touching sides and connect their diagonals , we form an equilateral triangle . therefore , each angle would be x = 60 . c"
Answer: C