This example shows the scale tone triads for the key of A minor, the chords derived from the natural minor scale. As you will seef the chords are exactly the same as those contained in the key of C major. This is because C major and A minor are relative keys. The only difference is the starting and finishing point - because the minor scale starts on A, A minor will now be chord I instead of VI.
As with major key scale tone chords, it is important to be able to play the chords in minor keys anywhere on the fretboard, particularly inversions along sets of strings. This will prepare you for any musical situation, as well as increase your choices for chord substitution. Take one inversion at a time and move it through all the chords in the key along a particular string group.