CTR+EDG allows you to create a circle by specifying
the center and a point on the edge (circumference) of the
circle.

Indicate a center location for the circle, using a 
Position Menu option.

Indicate the edge point of the circle in the same manner.

In 2-D construction mode, the center and edge points are
projected to the current construction plane, and the 
circle is created in the current construction plane.

In 3-D construction mode, the system locates a plane that 
is parallel to the current construction plane and passes
through the center point. The edge point is projected to
this plane and the circle is created in this plane.

