Hi (name deleted),

I saw that your constructions use "construct parallel line" liberally. In #1 (Duplicate segment), for example, the use of "construct parallel line" creates a suplicate segment that does not satisfy the given constraints. The directions are, "given a segment, a line, and a point on the line, construct a segment of the same length having the point as one endpoint." Your construction doesn't do this. You are assuming a segment and a point not on the segment. You then construct a line through that point parallel to the segment. So your construction doesn't generalize to the stated conditions. You can see the difference between the two at


Move point A or point B in this example. You'll see that the use of "construct parallel line" causes movements of A or B to affect your duplicate segment in ways that it couldn't be located on a given line, whereas the only thing affected in the second construction is the duplicate segment's length. Consider using circles constructed by point and given radius, instead of "construct parallel line".

You might examine your other sketches in light of this comment.

I'm sending this note to the listserv because I believe it could benefit everyone. If any of you object to my doing this as a matter of practice, just let me know.


Dr. T.

Pat Thompson