Problem: what is the measure of the angle x made by the diagonals of the any adjacent sides of a cube .
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"
annotated_formula: divide(const_180, const_3)