Skip to content

Polyline PLINE (Command)

Creates a connected sequence of line and arc segments as a single polyline entity. Unlike the LINE command which creates separate line entities, PLINE creates one unified object.

Quick start

Toolbar > Draw > Polyline, or type PLINE in the Command Panel


Prompts

Prompt Description
Specify start point First point of the polyline
Specify next point Additional points — segments are drawn between consecutive points

Keywords

Keyword When available Description
Arc In Line mode Switch to arc segments
Line In Arc mode Switch back to line segments
Length In Line mode Specify a segment length in the current direction
Close After 3+ points Close the polyline back to the start point
Undo After first point Remove the last vertex

How to Use

Command: PLINE
Specify start point: 0,0
Specify next point [Arc/Length/Undo]: 50,0
Specify next point [Arc/Length/Close/Undo]: 50,30
Specify next point [Arc/Length/Close/Undo]: Close

Line Segments (Default)

By default, PLINE draws straight line segments between points:

Command: PLINE
Specify start point: 0,0
Specify next point [Arc/Length/Undo]: 100,0
Specify next point [Arc/Length/Close/Undo]: 100,50
Specify next point [Arc/Length/Close/Undo]: (Enter)

Arc Segments

Type Arc to switch to arc mode. Arc segments are tangent to the previous segment direction:

Command: PLINE
Specify start point: 0,0
Specify next point [Arc/Length/Undo]: 50,0
Specify next point [Arc/Length/Close/Undo]: Arc
Specify next point [Line/Close/Undo]: 80,30
Specify next point [Line/Close/Undo]: Line
Specify next point [Arc/Length/Close/Undo]: 80,60

The arc bulge is automatically calculated to be tangent to the previous segment.


Length Option

Specify a segment length that extends in the direction of the current segment:

Command: PLINE
Specify start point: 0,0
Specify next point [Arc/Length/Undo]: 50,0
Specify next point [Arc/Length/Close/Undo]: Length
Specify length: 30                     --> extends 30 units in same direction

Close

Type Close (available after 3 or more points) to connect the last point back to the first:

Command: PLINE
Specify start point: 0,0
Specify next point [Arc/Length/Undo]: 60,0
Specify next point [Arc/Length/Close/Undo]: 60,40
Specify next point [Arc/Length/Close/Undo]: Close    --> connects to (0,0)

Undo

Type Undo to remove the last vertex without ending the command.


Polyline vs Line

Feature PLINE LINE
Entity type Single polyline entity Individual line entities
Arc segments Supported (Arc keyword) Not supported
Close Closes as one entity Closes with separate line
Selection Select entire shape at once Each segment is independent
Offset Offsets entire shape Offsets one segment

Best Practices

Practice Benefit
Use PLINE for closed shapes Single entity, easier to select/edit
Mix Line and Arc segments Smooth transitions in one entity
Use Close for closed shapes Ensures proper closure
Use PLINE for hatch boundaries Cleaner boundary definition
Use Length for known segment lengths Quick extension without calculating endpoints

Quick Reference

Task Input
Start polyline PLINE → start point → next points
Switch to arc segments Type Arc
Switch to line segments Type Line
Extend by length Type Length → enter distance
Close the polyline Type Close (after 3+ points)
Undo last point Type Undo
End without closing Press Enter

See also: Line Command | Spline Command | Arc Command