How can there be interference of light rays in Bragg's law

[tsopa]

As we know, Bragg's law is based on the path length difference between light which interfere with themselves after being scattered from atoms in the crystal.
If you google "Bragg's law", you will see numbers of pictures showing two light rays being scattered from two different atoms. Those two light rays are PARALLEL to each other.
How can those scattered light (which are parallel to each other) interfere with each other? And where does the interference happen?

 

[tsopa]

I got it. Nover mind :D

 

[Vita rockz]

Please explain for me

 

[Anthus]

yeah, this ray is not a single line. This line represents only the direction of movement of wave front. A wave front spreads perpendicular to that line.