# Revival Of This Problem. Part 1

Geometry Level 4

For the cube shown above, let

$v = \cos^2 w + \cos^2 x + \cos^2 y + \cos^2 z.$

If $$v$$ is in the form $$\frac{c}{d}$$, where $$c$$ and $$d$$ are coprime positive integers, find $$c+d$$.

Note: $$w$$, $$x$$, $$y$$ and $$z$$ are all angles between 2 diagonals of the cube.

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