You can add freeforms and other drawing objects only to a chart. You cannot add them to the datasheet.
On the Drawing toolbar, click AutoShapes, and then point to Lines.
Click Freeform to draw an object with both curved and straight segments. Drag to draw freehand shapes; click and move the mouse to draw straight lines.
Click Scribble when you want an object to look as if it was drawn with a pen.
To end a shape and leave it open, double-click it at any point.
To close a shape, click near its starting point.
Tip After you complete a freeform, you can close an open shape or open a closed one. Right-click the shape, and then click Close Curve or Open Curve on the shortcut menu.