O to A, it is x1 and this side O to, actually if you make this is A, if I make this is your A′, then OA′ is x1, and if this is B, if we make this is B′ then your OB′ is x2 right, and distance between this two point; that is A′ and B′, it is horizontal distance it is L say right.
जर B ला B′ असे गृहीत धरले तर OB′ हे अंतर x2 आहे. A′ आणि B′ मधील अंतर L असेल.