This is the three four time signature.
In the following example, the notes and rests all add up to the equivalent of three quarter notes per bar. Notice that a dotted half note goes for a whole bar in ^ time.
This melody in ^ time makes use of dotted half notes and dotted quarter notes. Using a separate sheet of paper, copy the notes and write counting numbers under them at first if you need to, and practice slowly with your metronome.