# CENTERLINE Command
[GstarCAD 2027](Help%20System/GSTARCAD/2027/Index.md) → [Commands](Help%20System/GSTARCAD/2027/Commands/(Commands).md) → [C](Help%20System/GSTARCAD/2027/Commands/C/(C).md)
## Function Description:
This command is used to create centerline geometry associated with selected lines and linear polyline segments.
## Command Access:
> **Icon:** 
> **Menu:** /
> **Ribbon:** Annotation > Centerlines > Centerline
> **Toolbar:** Centerline > Centerline
> **Command:** CENTERLINE
> **Alias:** /
> **Shortcut:** /
**Command Prompts: /**
```
Select first line:
```
```
Select second line:
```
## Operation Steps:
1、As shown in the figure, select the two side edges of the left trapezoid respectively to create centerlines.
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[Original help](https://www.gstarcad.net/help/GstarCAD_2027_en-US/detail/commandReferences_C/CENTERLINE.html) · © Gstarsoft Co., Ltd.