The Modify Shape dialog box enables you to specify shape you want to apply to selected object(s).
To set a predefined shape, just select the shape from the Predefined Shapes list.
To save your custom shape, set a new shape by dragging the select handles before entering the dialog box. Open the dialog box and click the Save As� button. The Save As dialog box will open, where you can enter a new name for the Shape, or choose to overwrite an existing one from the list of predefined shapes.
To delete a shape from the library, select it and press the Delete button.