What is the
minimum number of strokes to reproduce the drawing below without lifting up the pencil from the paper (no tricks at all), and without passing over a line segment (or part of it) already drawn? You may begin and end wherever you like, and line segments may cross each other, but only as intersections.
Note: a new stroke occurs when a line type ceased because you have to stop and change direction.
(In reply to
re(11): No Subject | spoiler | by pcbouhid)
BC is both a line segment and a stroke. Each additional stroke is also a line segment, except for the single stroke required to make the circle.
The motion you make when you first bring the pencil down to the paper to your starting position doesn't count as a stroke. But from there, you must stop and change direction.
Please write to the mathemetician.