SKETCH allows you to generate a continuous polyline entity
along a selected number of vertices.

Cursor-indicate the desired start point of the polyline.

Continue to sketch by pressing and holding the cursor 
button as you move the cursor in the direction of the
desired shape.

The cursor button can be released for desired vertices,
then pressed again to continue the sketch.

End the polyline in one of two ways:

- by choosing the BACK-UP, or ESCAPE option before 
  pressing <Enter>. Choose YES to store the polyline, or 
  NO to remove the polyline and create a new one.

- by pressing <Enter> when the polyline is complete. This
  automatically ends and stores the polyline at the last 
  point indicated.

In 2-D construction mode, the vertices are projected to 
the current construction plane, and the polygon is created
in the construction plane.

In 3-D construction mode, the polygon is created using the
3-D coordinates of the indicated vertices.
