public TinEdge GetPreviousEdgeInTriangle()

{
  // nodes of the edge
  var nodes = edge.Nodes;

  // edge geometry
  polyline = edge.ToPolyline();
  // edge length
  var length = edge.Length;
  // is the edge "inside"
  var isInsideEdge = edge.IsInsideDataArea;
  // edge type - regular/hard/soft
  var edgeType = edge.EdgeType;

  // get next (clockwise) edge in the triangle
  var nextEdge = edge.GetNextEdgeInTriangle();
  // get previous (anti-clockwise) edge in the triangle
  var prevEdge = edge.GetPreviousEdgeInTriangle();

  // get opposite edge
  var oppEdge = edge.GetNeighbor();

  // get left triangle
  var leftTriangle = edge.LeftTriangle;
  // get right triangle
  var rightTriangle = edge.RightTriangle;
}