el3ktr1k

If I take a photo of an object from two different points of view, how can I compare the relative angle of the object to another object within both pictures? For example, if took a photo of railroad tracks while standing on the ground, the angle of one track to the other will appear to be greater than zero degrees. However, if I take the picture from a hot air balloon the tracks will appear to be parallel. Is there a way to show mathematically that the tracks did not move and that they were always the same angle relative to each other? Thanks for any help.