Watch the Diatonic Triads in A online guitar lesson by Brad Carlton from Guitar Lab: Solid Strumming
This lesson presents the diatonic triads in the key of A. They are as follows: A the I chord, Bm the ii chord, C#m the iii chord, D the IV chord, E the V chord, and F#m the vi chord. We will not be dealing with the chord built off the seventh step of the major scale.
You will receive a fingerboard diagram chart displaying all six of these diatonic triads as well as the A major scale in first position. You will also receive an alternate chord for the iii chord. This chord will be the I chord over the III bass note.