The four margins of a page, in points, between the media box edges and the content area text flows in.
public PageMargins(double Left, double Top, double Right, double Bottom)
The distance from the left edge.
The distance from the top edge.
The distance from the right edge.
The distance from the bottom edge.
ISO 32000-2 §14.11.2 (page boundaries): the margins are measured inside the media box in default user space.