The Dimension toolbar contains commands to dimension elements of your symbol.
SmartDimension  Places several different dimensions. For more information, see SmartDimension Command. 

Distance Between  Places a linear dimension that measures the distance between elements or key points. For more information, see Distance Between Command. 

Angle Between  Places a dimension that measures the angle between elements or key points. For more information, see Angle Between Command. 

Axis  Sets a dimension axis for a drawing. For more information, see Axis Command. 

Coordinate Dimension  Places a dimension that measures the distance from a common origin to one or more key points or elements. For more information, see Coordinate Dimension Command. 

Symmetric Diameter  Places a dimension that measures the distance between a center line and another element or key point. For more information, see Symmetric Diameter Command. 

Measure Distance  Measures the distance between points in free space or between key points. For more information, see Measure Distance Command. 

Measure Distance Along  Measures the distance along a linear object based on two points. For more information, see Measure Distance Along Command. 

Measure Area  Displays the most recently selected area of the boundary in the current units. For more information, see Measure Area Command. 