Extend

The extend command stretches the nearest endpoint of a hovered Line, Arc, Ellipse, or open Polyline to the closest intersection it would form with another entity in the drawing. Hover near the endpoint you want to extend — a preview shows the extended entity — then click to apply.

Only entities with an actual endpoint can be extended. A Circle and a full (360°) Ellipse are always closed shapes with no endpoint, so they can never be extended — same for a closed Polyline or Rectangle. A partial Ellipse (an elliptical arc) and an Arc do have endpoints and extend the same way a Line does.

Extending an entity

1. Type extend in the terminal or click the Extend toolbar button.
2. Hover near one end of the entity you want to extend — the preview shows it extended to the nearest boundary in that direction.
3. Click to apply the extension.

The command stays active after each extension, so you can continue hovering and clicking to extend more entities. Press Enter, Space, or Escape to exit.

  Before:                      After:

  ──────           |           ──────────────|
  (short line)     (boundary)  (extended to boundary)

How the endpoint is chosen

The command looks at which end the cursor is closer to:

• Line and open Polyline — cursor nearer the end point extends the end forward; cursor nearer the start point extends the start backward.
• Arc and partial Ellipse — cursor nearer one angular end grows the arc in that direction, sweeping around the same center and radius (or the same ellipse shape) until it reaches the next boundary.

A ray — or, for Arc and Ellipse, the entity’s own underlying circle or curve — is cast from the chosen end, and the closest intersection with any other entity (excluding the entity itself and the ignored types) becomes the new endpoint.

If no intersection is found in that direction, no preview appears and clicking does nothing.

Boundary exclusions

The following entity types are ignored as boundaries — an entity does not extend to meet them:

• Text / Mtext
• Multileader
• Spline

All other types (Line, Arc, Circle, Ellipse, Polyline, Dimension) serve as valid boundaries.

If a Polyline’s first or last segment is itself an arc segment (drawn with the Arc toggle), extending it grows the arc along its own circle — the same way extending a standalone Arc does — rather than treating it as a straight segment.

Keyboard reference

Supported entities

Extend vs Trim