Originally Posted by: gmixstudioshi why is 2nd triad in major scale minor

Did you look at the tutorial I linked above?

A brief overview of music theory:
http://www.guitartricks.com/tutorial.php?input=495

If you will look at the 4th and 5th lessons of that tutorial in particular you will see the answer to your question:
http://www.guitartricks.com/lesson.php?input=11526&s_id=495

If you build a chord on every note of the major scale, using only notes from that one major scale, then you will get a very specific set of chords as a result.

The second chord happens to be minor because of the distance between it's notes; it has the formula of a minor chord!