ahh, good ol' quadrilaterals. Geometry was always my favorite math class in early schooling. I can still easily recall all of the associated formulas! Most of my schooling from those days hasn't really stuck, much of it from other subjects has been lost over the years as I realized it was a subjective view of teaching so-called 'facts,' and that's what I always liked about math, it's proofed and cannot be subjective (for the most part)