Fringe spacing of the Interference pattern due to two Coherent waves

[Baibhab Bose]

Homework Statement

In the attached image.

Relevant Equations

formulas of fringe width and phase differences I think.

Homework Statement: In the attached image.
Homework Equations: formulas of fringe width and phase differences I think.

It has been a long time since I have dealt with these kinds of interference/fringewidth problem, I can't figure out a way to start solving this problem. I was thinking about what the spacing between each of these wave-lines signify, and exactly which of them would create the pattern. Because of its oblique incidence, each wave would individually create patterns, so how do the two patterns make a final one?i think the fringewidth of the final pattern is asked here!

 

[BvU]

Because of its oblique incidence, each wave would individually create patterns

No. What makes you think that ?

Equations: formulas of fringe width and phase differences I think.

Way PF works is that you list the relevant equations and post an attempt at solution.
So re-read your old stuff or read up from some other source...
We don't give classes you missed or forgot and we don't do your homework -- it would only rob you from the rxercise...