[Perpendicular 1] command generates a perpendicular line to an existing curve.
For the prompt Specify start point
, specify a point on the target curve.
Typing B key, the 1st point becomes a middle point of the tangent, instead of the start point.
Typing P key changes the mode to the one that the start(or middle) point should not be on-curve point.
For the prompt
Specify the end point
, specify the end point of the perpendicular.