Triads and Scales Degrees

The following table shows the scale degrees where we find each type of triad:

Triad Major Scale Minor Natural Scale Minor Harmonic Scale Minor Melodic Scale
Major I, IV, V III, VI, VII V, VI IV, V
Minor II, III, VI I, IV, V I, IV I, II
Diminished VII II II, VII VI, VII
Augmented - - III III

Knowing the type of triad formed on each scale degree may be very helpful when identifying triads.