The Augmented chord is the final of these "simple," three note chords. Like the Minor and Diminished, it is also just a step away from the Major chord. To augment means to increase, so to make an Augmented chord, simply take any Major chord, and raise its fifth one half step.
F Maj to F Aug |
B Maj to B Aug |
Here is the final addition to our simple chart. Notice that the Augmented chord is placed to the right the Major chord, reflecting the "raised" character of its construction. Similarly, the Minor and Diminished chords are placed to the left of the Major chord, because of the "falling" nature of their thirds and fifth.
Here is the chart as applied to a C chord: