All set of vertices are in relation to P, the central point in the diagram.
In the 1st pair: The second term is a triangle formed with the lines passing through P and the points adjacent to N and H on either side of triangle PNH, that is, FA and ID. Hence the 2nd term in the 1st term is PDA. Similarly, point adjacent to D is M (on MJ), and that to L is B(on BG), the required triangle will be PGJ or PJG.
