Dimensions in ABAQUS/CAE are used to precisely control sizes and distances, to annotate reference values, and to create parameters that are, in turn, used to define equations relating different pieces of geometry. You can edit any dimension in a sketch as follows:
Change the dimension value. Changing a dimension value modifies the associated Sketcher geometry.
Designate the dimension as a reference dimension. Reference dimensions indicate quantities whose values are controlled elsewhere in the same sketch or dimensions of reference geometry that are controlled in another sketch.
Associate the dimension with a parameter. Parameters control Sketcher geometry by defining relationships between different pieces of geometry, including reference geometry.
To edit dimensions:
From the tools in the Sketcher toolbox, select the dimension modification tool 
. For a diagram of the tools in the Sketcher toolbox, see “The Sketcher tools,” Section 19.4.1.
ABAQUS/CAE displays prompts in the prompt area to guide you through the procedure.
Select the dimension you want to change.
ABAQUS/CAE highlights the selected dimension and opens the Edit Dimension dialog box.
Enter a new value for the dimension.
Note: You cannot edit the value field for reference dimensions or for parameters whose values are defined using an equation.
Toggle Reference to switch between a standard dimension whose value is used to control the sketch geometry and a reference dimension that reads the current value from the geometry.
Click f(x) to associate the dimension with a new parameter or to edit a previously associated parameter.
ABAQUS/CAE opens the Parameter Manager for editing. For more information, see “Adding and editing parameters,” Section 19.12.5.
When you are finished, click Apply in the Edit Dimension dialog box to update the sketch.
ABAQUS/CAE updates the dimension and geometry as required. If your edits result in an overconstraint, the conflicting constraints, dimensions, and parameters are indicated in magenta (for more information, see “Fully constrained geometry,” Section 19.7.4).
To edit more dimensions, repeat the above steps beginning with Step 2.
When you have finished editing dimensions, either
Click mouse button 2 anywhere in the ABAQUS/CAE window, or
Select any other tool in the Sketcher toolbox, or
Click the cancel button 
in the prompt area, or
Click the dimension modification tool in the Sketcher toolbox.
