Formulas for all types of 3 note chords

major = 1 3 5 minor = 1 3 5 augmented = 1 3 5 diminished = 1 3 5 sus2 = 1 2 5 sus4 = 1 4 5

So a C chord is C(1) E(3) G(5).
major = 1 3 5 (C E G)

Knowing that the formula for minor is 1 3 5, you will lower the E(3) to an E(3) for a Cm chord.
minor = 1 3 5 (C E G)

Augmented is 1 3 5, so in a C augmented you will raise the G(5) to a G(5).
augmented = 1 3 5 (C E G)

A diminished chord is 1 3 5, so for a C diminished you will lower the E(3) to an E(3) and the G(5) to a G(5).
diminished = 1 3 5 (C E G)

We will look at sus2 and sus4 chords shortly.

Page 1, How to spell different 3 note chords intro

Page 3, examples for major, minor, augmented and diminished