Trim

The trim command removes the portion of a Line, Arc, Circle, Ellipse, or Polyline that lies between two adjacent intersection points, splitting the entity into one or more remaining pieces. The segment to cut is determined by the cursor position — hover over the part you want removed and click to trim it.

Trimming an entity

Type trim in the terminal or click the Trim toolbar button.
Hover over the segment you want to remove — a preview highlights exactly the portion that will be cut.
Click to remove that segment.

The command stays active after each trim, so you can continue hovering and clicking to cut more segments — on the same entity or a different one. Press Escape to exit.

  Before:                     After trimming middle segment:

  ──────●──────●──────        ──────●          ●──────
      intersect  intersect       (left part)  (right part)
                                 (middle segment removed)

How the trim segment is determined

The command projects the cursor position onto the hovered entity and finds all intersection points it has with other entities. These intersections divide the entity into segments — for a Line, Arc, or open Polyline, the entity’s own endpoints act as additional fixed boundaries. A full Circle or Ellipse, or a closed Polyline (including a Rectangle), has no endpoints of its own, so at least two intersection points are needed before it can be trimmed at all. The segment whose interval contains the cursor’s projection is highlighted and will be removed on click.

Line, Arc, and open Polyline — the removed segment can be the leading portion (before the first intersection), a middle portion (between two intersections, splitting the entity into two pieces), or the trailing portion (after the last intersection).
Circle, Ellipse, and closed Polyline/Rectangle — since there is no fixed start or end, only the arc between two intersection points can be removed. With fewer than two intersections, no preview appears and clicking does nothing. The rest of the shape becomes the single remaining piece.

What trimming produces

Entity	Result after trimming
Line	Up to two shorter Line entities
Arc	Up to two shorter Arc entities
Circle	One Arc entity — the circle’s closed shape is gone, so the remaining piece is stored as an arc
Ellipse	One Ellipse entity with a start and end angle — the remaining piece stays an Ellipse, now a partial one
Polyline (open)	Up to two shorter Polyline entities
Polyline (closed) / Rectangle	One open Polyline entity — the closed shape is gone, so the remaining piece is stored open

Keyboard reference

Key	Action
`Escape`	Exit trim mode

Supported entities

Entity	Can be trimmed?
Line	Yes
Arc	Yes
Circle	Yes — requires 2 or more intersection points
Ellipse	Yes — requires 2 or more intersection points
Polyline (open)	Yes
Polyline (closed) / Rectangle	Yes — requires 2 or more intersection points
Text, Spline, Dimension, Leader	No

The entities used as cutting boundaries can be a Line, Arc, Circle, Ellipse, or Polyline. Text, Spline, Dimension, and Leader entities never register intersections, so they can’t act as boundaries either.

Trim vs Extend

	Trim	Extend
What it does	Removes a segment of an entity	Stretches a line endpoint to a boundary
Trigger	Hover over the segment to cut	Hover near the endpoint to extend
Result	Entity splits or shortens	Line endpoint moves to the boundary
Supported entities	Line, Arc, Circle, Ellipse, Polyline	Line only