Here is the A Chord, In the diagram you will see that all the fingers are directly behind the 2nd fret on the B, G, & D string. However when you place you fingers on the fretboard you will actually place the fingers in a slightly diagonal line.
Place the 3rd finger on the B string 2nd fret first as close to the 2nd fret as you can. Then place the 2nd, the 3rd fingers onto the fret board on the indicated strings and frets.
You will have to apply slightly more pressure on the fretboard on the G and D strings to ensure you don't here any fret buzz caused by the fingers being farther away from the frets.