When you are using the Sketcher to sketch features, you can use the underlying grid and preselection to position the cursor and create or modify sketch geometry. In addition, you can use the following techniques to position the geometry precisely:
Entering coordinates
When you are using the Sketcher to create a feature and Abaqus/CAE asks you to position a point (for example, to define the endpoint of a line or the center of a circle), you can do one of the following:
Select a point on the sketch using the Sketcher grid, existing vertices, or preselection.
Enter the desired X- and Y-coordinates of the point in a text box in the prompt area.
To help you determine the coordinates to provide, the X- and Y-axes of the sketch are indicated by dashed lines, which intersect at the origin of the sketch. The coordinates that you specify are relative to this origin. In addition, when you select a Sketcher tool, the coordinates of the current cursor position are displayed in the upper-left corner of the viewport, and you can use these coordinates as a guide.
Creating and modifying dimensions
After you have created the geometry, the Sketcher allows you to add dimensions between lines and vertices and other pieces of geometry in the sketch. You can then refine the sketch by replacing these dimensions with precise dimensions, and the sketch changes to reflect the new dimensions. In addition, dimensions allow you to annotate sketches for future reference.
You add dimensions by selecting the dimension tool 
in the Sketcher toolbox or by selecting Add
Dimension from the main menu bar—editing the dimension value is the final step in creating a new dimension. To modify an existing dimension, select the modify dimension tool 
from the Sketcher toolbox or select EditDimension from the main menu bar. For detailed instructions, see “Editing dimensions,” Section 20.13.
