NetTopologySuite : Detect Boundary from Intersecting linestrings

[Harilal]

I have three LineStrings as shown in the picture attached. I want to extract the enclosed area  formed by the intersection of these lines, as a single LinearRing. Could someone kindly give a clue on how to do this?

[FObermaier]

This is the way to go:

// sample geometries

var rdr = new WKTReader();
var geoms = new[] {rdr.Read("LINESTRING (0 0, 20 0)"),
    rdr.Read("LINESTRING (20 -5, 9 15)"),
    rdr.Read("LINESTRING (11 15, 0 -5)")};

// node the geometries by performing a union
var geom = OverlayNGRobust.Union(geoms);

// create a polygonizer, add noded boundary lines
var polygonizer = new Polygonizer();
polygonizer.Add(LineStringExtracter.GetLines(geom));

// Get the polygon
var polys = polygonizer.GetPolygons();