Question

What is the angle between any two diagonal of a cube ??

Answer 1

Here is your answer!

Let a be the side of cube. and O be its center and A and B be two vertices

The long diagonal is sqrt of a. that is a^1/2.

Let us consider triangle OAB

OA= OB=half of diagonal=1/2(a^1/2) and AB=a

This is an isosceles triangle with angle O=60 degrees.

So the angle between the two long diagonals of a cube is 60 degrees