The term used to describe parallel lines which appear to converge in the system of A. linear perspective.

B. Horizon Line

C. Orthogonal Lines

D. Vertical Lines

It depends on what type of third separates the three notes.for example: if you have two mayor thirds is an "aumented chord"if you have two minor thirds is an "diminued chord"if you have one mayor first and then one minor is a "mayor chord"and inverted is a "minor chord"