[4 Points] command generates a line segment after specifying a line(base line) that the line to generate lies on.
For the prompt
"Specify the start point of the base line"
, specify the start point of
the base line. An arbitrary point can be input.
For the prompt
"Specify the terminate start point of the base line"
, specify the
terminate point of the base line. An arbitrary point can be input.
For the prompt
"Start point of the line"
, specify the start point of the line to
generate. Mouse cursor point will be projected onto the base line.
For the prompt
"Terminate point of the line"
, specify the terminate point of the line
to generate. Mouse cursor point will be also projected onto the base line.
Pressing B key, the line segment length will be doubled by setting the previous input point be the middle point of the line.