Circle with center point and radius/point :
Determine circle via Center point and Radius.
Click on midpoint (in "free space" not visible!).
"Draw" circle by moving the cursor and set with mouse-click.
Set exact position and radius via the Change parameter window.
Circle through 3 points :
Determine circle with three points (free points, endpoints of a line, midpoint of a circle, etc.)
Example: Endpoint of a line
Click on first point.
Click on second point.
Set exact position of point or points via the Change parameter window.
Create circle tangent to 2 elements (circle/line/arc) :
Create tangential circle at Lines, Arcs and circles.
Example: Circle to coordinate axes.
Click on first spanning point.
Click on second spanning point.
By moving cursor, "pull" the circle and fix it via mouse-click.
Set radius in Change parameter window.
If you no longer want a Circle to be displayed, delete it provisionally (see Section 7.9.3.7, “Delete ”). Do not set radius to "0"!