Placement is a constant that is used on bar chords, fifth chords and now scales. As you may have noticed right from the start when you first learnt your open chords there was mention of root notes. Root notes are the key to naming all out chords and scales. It is as simple as knowing this...
What ever note you start your scale from, then that is the name of your scale! Providing the note you start from is the root note.
