If you take every other note in the C diatonic scale and play three note chords:
C-E-G = CMa
D-F-A = Dmi
E-G-B = Emi
F-A-C = FMa
G-B-D = GMa
A-C-E = Ami
B-D-F = Bdim

If you take every other note and play 4 note chords:
C-E-G-B = CMa7
D-F-A-C = Dmi7
E-G-B-D = Emi7
F-A-C-E = FMa7
G-B-D-F = Gdom7 or G7
A-C-E-G = Ami7
B-D-F-A = Bhalf-dim or Bmi7b5