How do warm-ups, relaxation techniques, and vocal excercises actors?

They help the actor eliminate stage fright and help in preparedness.

They help our bodies to transition into a more workable state mentally, physically, and vocally while showing strengths and weaknesses to the person doing the exercises. It also guards against future injuries. I personally have seen them used to assert dominance.

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"