code: public final void addTriangle(double x1, double y1, double x2, double y2, double x3, double y3) {
  		addEdge(x1, y1, x2, y2);
  		addEdge(x2, y2, x3, y3);
  		addEdge(x1, y1, x3, y3);
  	}
docs: Adds edges of a triangle.