3 ENTS allows you to create a circle tangent to three
selected entities.

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

Select the second tangent entity.

Select the third tangent entity, near the point of 
tangency. You can cancel the selection by choosing the
BACK-UP option and selecting another entity.

If a tangent circle cannot be created (for example, 
because the selected entities are not coplanar and you are
in 3-D construction mode), an error message is displayed.
You are prompted to press <Enter> and to select a 
different entity as the first tangent entity.

In 2-D construction mode, the circle is created in the 
construction view, at the depth that is active when the
third tangent entity is selected.

In 3-D construction mode, the circle is created in the 
plane of the selected entities.
