Hi John
It would be very helpful for you to be more specific in your question. What exactly is not clear?
All layout solutions come from control of horizontal and vertical lines, planes and dimensions. Your framing square models hor. and vert. Your spirit level and plumb bob detects hor. and vert. You reference to hor. and vert. in sqaure rule by choosing adjacent square sides as layout faces. In scribe rule you orient and bench mark the timber to hor. and transfer dimension by plumb line projection. Your tools must be accurate. The former statements are the first princples.
Please restate your question lest you get a filibuster.
Roger
