In reply to Deadeye:
I could easily have mistakes, its certainly not an elegant solution.
Tough to explain without being able to use superscript but see if you get the gist:
Take top triangle and split into 2x right angled triangles by adding a perpendicular from A.
New top right triangle has a side of 294 and angle of 13.39°. Use trig to find other sides which gives 286 (right part of A) and 68 on the new line drawn in.
Top left triangle now has sides of B and 69. Pythagorus gives remaining part of A.
Now you can define A in terms of B: A=286+sqrt(Bsquared + 68squared)
Onto bottom triangle, drop another perpendicular in. Left traingle has an angle and B so can the other lengths are Bcos(13.39) and Bsin(13.39).
Right triangle has sides of A and BSin13.39, pythagorus gives the last side as sqrt(Asquared+BSin13.39squared).
So 694 = BCos13.39+sqrt(Asquared+BSin13.39squared)
Sub in A=286+sqrt(Bsquared + 68squared) and solve for B.
694 = BCos13.39+sqrt((286+sqrt(Bsquared + 68squared))squared+BSin13.39squared)