You'll have to rough cut the panels first, join them, and then loft on the panels. The lofting numbers tell you how far to go to the right and then up from a starting point. Be sure to start reading the instructions from the beginning. They describe the rough cutting and which rough cut panels to join.

By the way, I just got back from a wonderful three-day trip at San Miguel Island in Southern California. The photo journal is at the link below.