(Optional) Click the Profile option if you want to
create walls as you sketch.
Click to set the circle's center.
You can dimension the points relative to other
sketch objects.
Click to set the circle's diameter.
The circle will snap to existing sketches or determined circles and arcs
in the plane of the sketch.
If you sketch two circles that are tangent
to each other, and then change the diameter of one circle by editing its
dimension, tangency with the other circle is maintained.
If you drag
the center of a circle that is tangent to another circle, the radius of the
other circle changes to maintain tangency.
Circle in the
Sketch group or press
C.