they say 3 shapes and show 3 pictures, but two are the same... is this a mistake or no? if you look at the A on the 2nd fret 3rd string.. there is no way to figure this note out with the shapes given.
It's no biggee, but yes, with those patterns you're on your own to figure out the notes on the first two frets of the D and G strings. There is a pattern to find those four notes from other known roots, but it's easier just to memorize them. This method is predicated on your having memorized all the note-names for the low-E and A strings, so four more notes shouldn't be too hard.