Thanks for your inquiry. You can determine this distance if you use RelativeVerticalPosition.Page; For example
see the following code.
Document doc = new
Shape awShape = new Shape(doc, ShapeType.Image);
awShape.RelativeVerticalPosition = RelativeVerticalPosition.Page;
awShape.VerticalAlignment = VerticalAlignment.Bottom;
awShape.VerticalAlignment = VerticalAlignment.Center;
awShape.DistanceBottom = 50; //Set distance between shape and bottom of page.
But you can’t determine the end of page. Aspose.Words
document represents content and formatting of a document, not its layout into
lines and pages. This feature is called pagination and it is not released yet.
See FAQ for more information.