Formula: Root + Minor Third + Minor Third (1-♭3-♭5)
Unlike the major and minor triads, which include both major and minor thirds, the diminished triad has two minor thirds stacked from the root. There is a minor third from 1 to ♭3, and from ♭3 to ♭5. The symmetry is clear when the chord is played in root position. The diagram below shows a C diminished triad in root, 1st, and 2nd inversions.
The notes of a Cdim triad (C-E♭-G♭) on the fretboard are displayed below.
