Oops, I just noticed that the circle is offset from center so B-10' is not equal to A-10'
Your circles don't look like perfect radius.
Don't type in the radius - use snap points.
Your next step will be to determine the length of arc from 10-9.
Not the cord length (many books miss this) you need the arc length.
Once you find this it is the same for all (9-8 is the same as 10-9).
Tip- you can find the arc length by
copy and paste pie shape away from the drawing.
trim the pie
list the arc
Draw circle of R 10-9 arc length at point 10' in your flat development..
Draw circle of R A-9' at point A
Where these two circle intersect is point 9' you now have line A-9