Three equally spaced, coherent sources of water waves of frequency \(f\) are in a line with a distance \(d\) separating each adjacent pair. All three sources have the same amplitude. Nodal lines exist where the separate waves from the three sources cancel each other. Far from the sources, where we can treat the wavefronts from each source as parallel, what are the angles between the nodal lines in the water and the perpendicular to the line joining the sources?