The 2nd, 3rd, and 4th strings on the guitar are referred to as the 2nd set (2nd set of 3 strings).
All of the triads in the following exercises use the 2nd set only.
Root position triads
1st inversions
2nd Inversions
In the following exercise the voicings of each triad are played starting with the voicing closest to the nut of the guitar and ending with the one furthest from the nut.