I've been trying to design a three surface airplane using a book by Andy Lennon as a guide. My understanding of aerodynamics is limited, and my math skills poor,.. ( a perfect recipe for success? )

The book shows how to find 1/4 mac for a tapered or a swept design but not the combination. I need to determine the 1/4 mac of the tail plane in order to find a ballpark for the np and cg.

I've made a conceptual drawing and need to determine if its viable.

I looked at the 1/4 mac calculator in the sticky, it can't be used because I'm unsure how to determine the sweep of the tail plane as it was purely random. The drawing program being used is an older version of MS Paint so there is no way to figure the angle of sweep even if I knew the formula.

I need some kind of illustration.

Mick