Watch the Inverted Start online guitar lesson by Brad Carlton from Chord Studies: Evolving Triads Vol. 1
This is a I - IV -V progression in the key of A. We start off with an A chord in a second inversion triad using your first finger as a barre on the second fret. For good voice-leading we next play the D chord in first inversion. The idea here is getting the hang of these triads so that they can be used effectively in a progression.