The names of the vertices (or corners) are the letters next to them. However you may need to write the plot points, so you would look at the left side or the y axis and count where the dot is as a number. Lets say its D. D is 4 on the y axis. Then you would go straight down to find the x axis. It is right over three. than you would write it with the x axis ALWAYS first. So D is (3,4).
Hope it helped