Line/P,Perpto,L
Perpendicular Line Segment
Creates a perpendicular line segment from a point on a line. Direction selector (Left/Right) specifies which side.
What It Does
The Line/P,Perpto,L operator creates a line segment perpendicular to an existing line, starting at a specified point on that line. The segment length and direction (Left or Right) are specified.
Syntax
Line/P0, Perpto, L0, Length, Dir=Left|Right
Quick Input
P: [point on the reference line]
L: [reference line]
Length: [segment length in mm]
Dir: Left or Right
Direction Selector
The Dir selector specifies which side of the reference line the perpendicular segment extends:
| Dir | Result |
|---|---|
Left | Segment extends to the left of the line direction (or upward for horizontal lines) |
Right | Segment extends to the right of the line direction (or downward for horizontal lines) |
Worked Examples
Setup:
L0 = Horizontal line at Y=0
P0 = (40, 0) [point on L0]
Line/P0, Perpto, L0, Length=100, Dir=Left
→ L1: from (40,0) to (40,100) [upward]
Line/P0, Perpto, L0, Length=100, Dir=Right
→ L2: from (40,0) to (40,-100) [downward]
Analytic Rule
Perpendicular direction = normal to L0 at P0.
For horizontal L0: perpendicular is vertical.
For vertical L0: perpendicular is horizontal.
For angled L0: perpendicular slope = -1/slope(L0)
Dir=Left/Right selects which side of P0 the segment extends.
Result: Exact analytic perpendicular segment.
FAQ
Is Dir=Left/Right mandatory?
Yes. Dir is part of the operator syntax and is not optional. Without it, two solutions exist (one each side of P0).
Can I create a perpendicular bisector?
Yes. Create the midpoint of a line with Point/Midpoint,L, then use Line/P,Perpto,L through that midpoint to create the perpendicular bisector.