# DCDIAMETER Command [GstarCAD 2027](Help%20System/GSTARCAD/2027/Index.md) → [Commands](Help%20System/GSTARCAD/2027/Commands/(Commands).md) → [D](Help%20System/GSTARCAD/2027/Commands/D/(D).md) ## Function Description: Constrains the diameter of a circle or an arc. ## Command Access: Icon:  Menu Item: Parametric(P) > Dimensional Constrains(D) > Diameter(D) Ribbon: Parametric > Dimension > Diameter Toolbar: / Command Line: DCDIAMETER Command Alias：/ ## Command Prompts: ``` Select arc or circle: Specifies an arc or a circle to be constrained. ``` ``` Specify dimension line location: ``` ## Operation Steps: 1、Select circles as shown to add diameter constraints. 2、The diameter of the circle will be constrained.  --- [Original help](https://www.gstarcad.net/help/GstarCAD_2027_en-US/detail/commandReferences_D/DCDIAMETER.html) · © Gstarsoft Co., Ltd.