>>14052616Let x be the angle from a chord's endpoints to the center of a circle for a chord that divides the area of the circle into fraction F
x - sin(x) = 2 pi F
Now for two intersecting chords with angles y and z whose intersection has angle x and fraction of area F
cos(z/2) cos(x-y/2) csc(x-y/2-z/2) (1-cos(y/2) sec(x-y/2))^2-sin(x) cos(y/2) sec(x-y/2)+x = 2 pi F