WPF: How to apply a GeneralTransform to a Geometry data and return the new geometry?

PathGeometry geometry = new PathGeometry();
geometry.Figures.Add(new PathFigure(new Point(10, 10), new PathSegment[] { new LineSegment(new Point(10, 20), true), new LineSegment(new Point(20, 20), true) }, true));
ScaleTransform transform = new ScaleTransform(2, 2);
PathGeometry geometryTransformed = Geometry.Combine(geometry, geometry, GeometryCombineMode.Intersect, transform);

PathGeometry geometryTransformed = Geometry.Combine(Geometry.Empty, geometry, GeometryCombineMode.Union, transform);

Geometry inputGeometry = new PathGeometry();
var inputGeometryClone = inputGeometry.Clone(); // we need a clone since in order to
                                                // apply a Transform and geometry might be readonly
inputGeometryClone.Transform = new TranslateTransform(); // applying some transform to it
var result = inputGeometryClone.GetFlattenedPathGeometry();