If I have the size of two areas and then the size of the intersection. How may I work out the probability of if I changed an area, the new intersection would be smaller than the one I have?

ie: Total area is = 64800
Area 1 = 1186
Area 2 = 1777
Intersect = 75.36

Then I produce a new Area 2 which has the same size area but in a different place, how to I work out the question above?

Thanks