Draw Polygons on Grids
Wolfram Demonstrations Project · 2008
You can create drag store and delete points lines polylines and polygons. All vertices (of the currently edited polygon) now have locators associated so you can drag them and place them separately with the mouse. Also you can create and delete a vertex with a single mouseclick (CONTROL+ALT+Mouseclick in Windows).A host of options is provided (see details text).;