CTR-ENT allows you to create a circle tangent to a 
selected entity, with its center at an indicated position.

Select the desired tangent entity, near the point of 
tangency. If necessary, you can cancel the selection by
choosing the BACK-UP option and selecting another entity.

Indicate a position for the center of the circle by
selecting a Position Menu option.

If a tangent circle cannot be created (e.g., because the 
indicated center position is on the selected tangent 
entity), an error message is displayed. You are prompted
to press <Enter> and to select a different tangent entity.

In 2-D construction mode, the circle is created in the 
construction view, at the depth that is active when the 
center is indicated.

In 3-D construction mode, the circle is created in the 
plane of the selected entity and the indicated point.

To create another circle tangent to the selected entity,
indicate another center position.
