Use the Polygon menu item or toolbar button to draw polygons on the RockPlot2D screen display and record the X,Y coordinates of their vertices in the data pane.
The program will be in "Digitize Polygon" mode, as noted at the bottom of the screen.
! If you close the RockPlot2D window before copying the data to the clipboard, it will be lost. The data is not stored in the Rw2D file.