Which triad type is built from root, minor third, and diminished fifth?

Which triad type is built from root, minor third, and diminished fifth?

• A. Diminished Triad
• B. Major Triad
• C. Augmented Triad
• D. Minor Triad

Answer: (A)

Triads are named by the intervals from the root to the third and to the fifth. A diminished triad features a minor third above the root and a diminished fifth above the root. That exact stack—root, minor third, diminished fifth—defines the diminished triad. The diminished fifth is one semitone lower than a perfect fifth, giving the characteristic tense sound. If it were a major triad, the fifth would be a perfect fifth; if it were an augmented triad, the fifth would be augmented; if it were a minor triad, the third would be minor but the fifth would remain perfect. The given structure matches the diminished fifth, so it’s the diminished triad.

Triads are named by the intervals from the root to the third and to the fifth. A diminished triad features a minor third above the root and a diminished fifth above the root. That exact stack—root, minor third, diminished fifth—defines the diminished triad. The diminished fifth is one semitone lower than a perfect fifth, giving the characteristic tense sound.

If it were a major triad, the fifth would be a perfect fifth; if it were an augmented triad, the fifth would be augmented; if it were a minor triad, the third would be minor but the fifth would remain perfect. The given structure matches the diminished fifth, so it’s the diminished triad.