You can place dimensions anywhere in a drawing and you’ll find the Dimensions section on the Tools extension tab. There are tools for measuring horizontally/vertically/diagonally in both 2D and 3D, as well as tools for Angle dimensions, Radial dimensions, and Chain dimensions. 

Placing a dimension

Dimensions can be placed using 3-clicks, for increased control of the extension length, or 2-clicks, for faster placement.

Diagonal, vertical and horizontal dimensions are positioned in the 2D view and the 3D view using the same tool.

To place a 3-click dimension, follow these steps:

1. Go to the Tools extension tab and select the Dimension tool:
   
    
2. Move the cursor to either the 2D or the 3D drawing view. In the quick properties box in the top left corner of the view, the Associative checkbox is activated and the object you snap the dimension to is highlighted in blue. Click once to set the dimension's starting point.
   
    
3. Move the cursor in the desired direction and click again to set the dimension's ending point:
   
    
4. Move your cursor to adjust the length, which in this step is the distance between the dimension text and the distance being measured, or use the properties box to enter a precise length.
   
   Also in this step, you pick the dimension alignment - Diagonal, Vertical, or Horizontal - as described below.
   
   
    
5. Click one last time to place the dimension.
6. To place more dimensions, repeat steps 2-5.
7. When you are finished, press the Esc key or move the cursor off the drawing area to release the tool.

To place a 2-click dimension, select from the Tools extension tab, and follow Steps 2 & 3 above.

Copy a dimension

You can copy an existing dimension by selecting it and pressing the A key.

When copying a dimension, the following options are available in the Quick Properties box:

• Associative – Keeps the copied dimension associated with the object it measures.

• Keep length – Preserves the original dimension length instead of recalculating the measurement based on the new snap points. This option is disabled by default.

  Keep length enabled

• With Keep length selected, the copied dimension retains the original dimension length. You can snap the copied dimension to the corner (end point) of the preserved length for precise placement.

  

  Keep length disabled

• With Keep length un-checked, the copied dimension starts a new dimension. The measurement is recalculated based on the new snap points you select.

Dimension alignment
 

Diagonal

Vertical

Horizontal

Editing a dimension

When a dimension is selected in the drawing, the yellow stretch nodes can be used to adjust the dimension or the placement of the text.

1. Click and drag to adjust the length of the dimension. The small, blue dots at the end of the dimension legs indicate that the dimension is associative.
2. Click and drag to place the text above, below, or on the dimension line. The text can also be pulled outside of the line.
3. Click and drag to adjust the height of the dimension.

Dimension properties

For each dimension you can change its properties from the property box. Each dimension type has different sets of properties. To change them, select the dimension in 2D or 3D to bring up the quick properties box. 

2D dimension:

• Text Display: Choose the desired way to display the text with your dimension: Dimension only, Text only, Text and dimensions, Text and dimensions on 2 lines, or Text and dimensions on multiple lines.
• Text: Type the text you would like to show with or in the place of your dimension text.
• Line length: Increase or decrease the line length of the dimension. You can also do this with the stretch node of the top line of your dimension in the drawing view.
• Text rotated: Check this box to toggle between horizontal and vertical text.
• Auto-rotate Dimension: Keep this checkbox selected to make an associative dimension auto-rotate along with the object it is attached to, for accuracy and readability.
• Text Style: Use drop-down to select a pre-defined style or click Edit to customize Font, Font Height, Font color, and more. Choose between different text styles that you create in the Style Editor.
• Dimension Style: Use drop-down to select a pre-defined style or click Edit to customize Distance unit, arrow head type, and more.
• Arrows Outside: Places the arrow heads on the outside of the dimension line and remove the line between the two end lines.
• Highlight text: Highlights the dimension text to improve visibility against other drawing objects.
• Line Style: Use the drop-down to select a pre-defined style or click Edit to customize Width (thickness), type (solid, dashed, etc.), and more.

3D Dimension:

• Distance: Displays the measured distance of the selected dimension. This value is read-only and cannot be edited from the Quick Properties box.
• Line thickness: Sets the thickness of the dimension line. 
• Animate Text: When selected, the dimension text automatically rotates to remain readable as you change the view.
• Dimension alignment: Controls the orientation of the dimension text. Choose from Diagonal, Vertical, or Horizontal.
• Text Style: Selects the text style used for the dimension. Click Edit to modify the selected text style.
• Dimension style: Selects the dimension style used for the selected dimension. Click Edit to modify the selected dimension style.
• Line Color: Changes the color of the dimension line.

• Show in Render: When selected, the dimension is visible in rendered views. Un-check to hide dimension from renderings. 

  

Notes about automatic length in 2-click dimensions

When placing a 2-click dimension, the length of the extension leg is determined by its relation to nearby dimensions.

When one or more of the legs of the new dimension are placed inside of an existing dimension, the legs should end up shorter than the existing dimension:

When both legs of the new dimension are placed outside of an existing dimension, the legs should end up taller than the existing dimension:

In cases where there isn't ample space below an existing dimension, the dimension will snap above.

As is the case with any dimension, you can manually adjust the extension leg length after placement, if desired.