Of course, leaving aside all the technical drawing skills, all you need to do, as it's a day boat and presumably doesn't have large sails, is to go out on the water and sheet in the sail from the cockpit then play about holding the sheet down in different spots until you find the ideal where the leach neither opens too much or goes too flat and the foot curves nicely without being too straight. After all, that's what you are after, a nicely set sail and no amount of calculations will guarantee it'll be right in practice.
-------------------- If I can misunderstand, I will misunderstand.