A circle of radius 10 units is centered at \( (0, 0, 50) \). The plane it lies in, has a normal vector \( (1, 0, 0) \). A uniform direction ray of light falls on the circle, generating a shadow on the floor (which is the XY plane). The direction of the shadow is given by \( d = (1, -0.5, -0.75) \). The shadow is an ellipse. Find the sum of the semi-major and semi-minor axes of this ellipse.