You can add, edit, show, and delete dimensions; you can also specify how dimensions appear. 
 Edit Dimensions 
-  In a sketch, double-click the dimension you want to edit, or click the Dimension command in the Constrain panel and then click the dimension you want to edit. 
- In the Edit Dimension dialog box, do any of the following: - Enter a new value in the dimension field. 
- Click the arrow, choose Measure, and then click the geometric element whose measurement you want to use. 
- Click the arrow, choose Show Dimensions, and then click the geometric element you want to measure. 
- Click the arrow and choose a value from the list. 
 Note: You can also enter or edit an expression that defines a parameter. For example, enter HGHT = 5mm. The expression is parsed to create the parameter HGHT and assign it a value of 5 mm.  
-  Click the check mark to accept the new dimension. 
 Delete Dimensions 
- Select the dimension in the graphics window and press Delete, or right-click and choose Delete. 
 Show/Hide Dimensions 
 Make dimensions visible so you can edit them. 
 Change How Dimensions Appear 
- In an active sketch, choose one of the dimension display icons in the status bar: - Value: Displays sketch dimensions as the calculated value. 
- Name: Displays sketch dimensions as the parameter name. 
- Expression: Displays sketch dimensions as the specified parametric expression. 
- Tolerance: Displays sketch dimensions with a specified tolerance. 
-  Precise Value: Displays sketch dimensions as a value, ignoring any precision. 
 Note: You can also change how sketch dimensions appear by using the Dimension Properties dialog box. Right-click a dimension in the graphics window and choose Dimension Properties. In the Dimension Properties dialog box, click the Document Settings tab and choose an option from the Modeling Dimension Display menu.