How do I change the angular dimension in Autocad?

In AutoCAD, changing angular dimensions can refer to two main scenarios: modifying the appearance and properties of an angular dimension object itself, or adjusting the actual angles of specific objects, such as section lines.

How to Change Angular Dimensions in AutoCAD

Understanding which type of "angular dimension" you need to change is key, as the methods differ. Here, we cover both common approaches.

Changing the Appearance and Properties of Angular Dimension Objects

If you're working with standard angular dimension objects (created using the DIMANGULAR command or similar), you can modify their display, precision, text, and other visual properties.

Modifying Individual Angular Dimensions

To change properties of an existing angular dimension directly:

1. Select the dimension: Click on the angular dimension you wish to modify.
2. Open the Properties palette: Press Ctrl+1 or type PROPERTIES and press Enter.
3. Adjust properties: In the Properties palette, you can modify various settings under categories like:
   • Text: Change text height, color, offset, or force a specific text value.
   • Lines & Arrows: Modify arrowhead types, sizes, and dimension line properties.
   • Primary Units: Adjust the Precision (number of decimal places), Angle format (e.g., Decimal Degrees, Deg/Min/Sec), and Round off for the measured angle.

Defining Angular Dimension Styles

For consistent angular dimensions across your drawing, or to set default behaviors for new angular dimensions, you should use Dimension Styles.

1. Access Dimension Style Manager: Type DIMSTYLE or DDIM in the command line and press Enter. This opens the Dimension Style Manager.

2. Create or Modify a Style:

   • To create a new style, click New and follow the prompts.
   • To modify an existing style, select it and click Modify.

3. Adjust Settings in the New/Modify Dimension Style dialog box:

   • Lines tab: Control the appearance of dimension lines and extension lines.
   • Symbols and Arrows tab: Select arrowhead types and sizes for angular dimensions.
   • Text tab: Define text style, color, height, and placement for dimension text.
   • Primary Units tab: This is crucial for angular dimensions.
     • Units format: Choose the angular unit format (e.g., Decimal Degrees, Deg/Min/Sec, Grads, Radians, Surveyor's Units).
     • Precision: Set the number of decimal places for the angle display.
     • Zero suppression: Control whether leading or trailing zeros are displayed.

4. Set Current: After defining or modifying a style, you can set it as the current style for new dimensions by selecting it and clicking Set Current.

5. Apply to Existing Dimensions: To apply a new style to existing dimensions, select them in the drawing, then choose the desired dimension style from the Properties palette or the Annotate tab's Dimension panel.

Changing the Angle Dimensions of a Section Line (Specific Case)

If you are working with specific architectural or structural section lines in AutoCAD and need to change their defining angles, follow these steps:

1. Select the Section Line: Double-click the section line you want to modify in your drawing.
2. Access Properties Palette: Ensure the Properties palette is open (press Ctrl+1 if it's not).
3. Navigate to Angle Settings: On the Properties palette, click the Design tab. Expand the Basic Component Dimensions section.
4. Specify New Angle Values:
   • Enter desired values for Angle 1.
   • Enter desired values for Angle 2.
     These values will redefine the angular properties of the section line.
5. Deselect Grips: Right-click in the drawing area, and then click Deselect All to turn off the grips from the selected section line.

This method allows you to precisely adjust the defining angles of a section, which might affect its geometry or how it is represented in the drawing.