So let's explore the triad inversions on strings four, three, and two. I'm going to start up here in position, and I'm going to play a C major triad, starting with C at the tenth fret with my third finger, my second finger in E at the ninth fret, and then, with my first finger I'm playing G. That's root position, because we have the root note C in the bottom. And I'm going to work my way backwards.
So, I'm going to go down to the next note lower than C, which happens to be G. I'm going to try to find my other notes in the cord. I'm missing a C and an E. Well, it just so happens that those two notes line right up on the exact same fret. So that would be our second inversion, because we're working backwards.
Root position, second inversion, and then now the only note that's left over to put on the bottom is our E note. That's going to be right here. We're missing a G and a C, so we can play our G open and then a C at the first fret, and finally we have our first inversion.
So, from low to high we can say we have a C triad first inversion here, open position, to the fifth position, second inversion C major triad to root position C major triad in eighth position. There you have your triad inversions on string groupings four, three and two.