Can it be proved that there would be no change in the "fringe width" when the main illuminated slit(s) is shifted to a position, which makes an angle of $\Theta$ with the original position of the source slit?
My try - I first found out the fringe width in a normal double slit where the position of the source slit is unchanged. However, after that, As I tried for the new position of the slit, I got stuck and couldn't equate the two values of fringe width.