Grateful Dead Music Forum

Been reading up on chord theory, construction, formulas and such when I came across this site:

http://www.jazzguitar.be/jazz_guitar_chord_theory.html

It all makes a good deal of sense but the thing about major and minor thirds throws me off. Example:

It says on this page that to construct Cmajor you apply the major chord formula, 1 3 5. 1 to 3 is a major third and 3 to 5 is a minor third.....shouldn't the formula be 1 3 b5?

Same for F chord, A to C is a minor third, so why does the formula remain 1 3 5?

Is it just a mistake made by whoever made the page or is there more to it?

becuase the notes in question are the first, third, and fifth notes of their coresponding scales, the formula, while following intervalic patterns, isn't related to the intervals it's representing

So why in the case of Dm does F have to be shown as minor third(b3)? The result would still be the same if it was shown as just 3, or does this aplpy to all different scales where some notes wouldbecome sharps, i.e. mixo scale?

Here's the thing:

a Maj 3rd + a min 3rd = a perfect 5th

and

a min 3rd + a Maj 3rd = a perfect 5th