From the Selection toolbar, choose one of the
  following:
 - Rectangle
 
 
- 
  
 Click to indicate one corner of the rectangle, and drag the cursor
  to the second corner. This tool is selected by default.
  
  
- Circle
 
 - 
  
 Click to indicate the center of the circle, and drag the cursor to a
  point on the circumference.
  
  
- Polygon
 
 - 
  
 Click to indicate one vertex of the polygon, and drag the cursor to
  the second vertex. You then continue to click on each vertex of the polygon.
  Click mouse button 2 to indicate you have finished entering vertices. There is
  no limit to the number of vertices in the polygon.