# Control Dimension Geometry [GstarCAD 2018](Help%20System/GSTARCAD/2018/Index.md) → [User Guide](Help%20System/GSTARCAD/2018/User%20Guide/(User%20Guide).md) → [Dimensions](Help%20System/GSTARCAD/2018/User%20Guide/Dimensions/(Dimensions).md) → [Use Dimension Styles](Help%20System/GSTARCAD/2018/User%20Guide/Dimensions/Use%20Dimension%20Styles/(Use%20Dimension%20Styles).md) The appearance of dimension lines, extension lines, arrowheads and center marks can be managed.  Control Dimension Lines Controlling the dimension line properties like color, lineweight and spacing . Control Extension Lines Controlling the extension line properties like color, lineweight, overshoot and offset length. Control Dimension Arrowheads Controlling the arrowhead symbol's type, size and visibility in dimensions and leaders . Customize Arrowheads You can create your own custom arrowheads by defining a block. To use custom arrowhead, select Use Arrow option in the list of arrowhead and specify the name of the block definition. --- ## Other versions with matching text [GstarCAD 8 (2013–2014)](../../../../2013/User%20Guide/Dimensions/Use%20Dimension%20Styles/Control%20Dimension%20Geometry.md) · [GstarCAD 2015](../../../../2015/User%20Guide/Dimensions/Use%20Dimension%20Styles/Control%20Dimension%20Geometry.md) · [GstarCAD 2016](../../../../2016/User%20Guide/Dimensions/Use%20Dimension%20Styles/Control%20Dimension%20Geometry.md) · [GstarCAD 2017](../../../../2017/User%20Guide/Dimensions/Use%20Dimension%20Styles/Control%20Dimension%20Geometry.md) · [GstarCAD 2019](Help%20System/GSTARCAD/2019/User%20Guide/Dimensions/Use%20Dimension%20Styles/Control%20Dimension%20Geometry.md) · [GstarCAD 2020](Help%20System/GSTARCAD/2020/User%20Guide/Dimensions/Use%20Dimension%20Styles/Control%20Dimension%20Geometry.md) · [GstarCAD 2021](Help%20System/GSTARCAD/2021/User%20Guide/Dimensions/Use%20Dimension%20Styles/Control%20Dimension%20Geometry.md)