If the axis of the Earth is tilted at 23.4 degrees away from the North Ecliptic Pole, and the Ecliptic Plane is tilted at 60.2 degrees away from the North Galactic Pole, then why is the Earth's rotational axis inclined at 27.13 degrees relative to the Galactic Equator instead of (90-(60.2+23.4)) = 6.4 degrees? Is there a formula that will allow me to calculate this, and if so, can anyone show me how to do it? I know it involves spherical trigonometry. I'm somewhat familiar with transformations of galactic, ecliptic and equatorial coordinate systems and spherical trigonometry. But I can't find the formula that will allow me to transform Equatorial coordinates to Galactic coordinates. Here is a diagram which may or may not help. It at least illustrates my dilemma. Thanks!