Root on A string
no fifthx-10-9-10-10-x
G9 is the G dominant 9 chord. Its notes are G, B, D, F and A. A dominant seventh with a ninth added. Try it in a blues turnaround.
x-10-9-10-10-x
Numbers show frets from the low E string to the high e string; x means don't play that string.
Every G, B, D, F and A on the first 12 frets. The filled dots are the root, G. Build your own shape from any nearby group.
Other G chords
Other dominant 9 chords