When an object is selected in the Viewer, or on the Model tree, it's properties are displayed in the Properties panel.
Values can be dragged from the Properties panel to create measurements.
The properties window can be moved around the screen as required. See Controlling Areas of the Screen.
Comparison Summary
The nature of the difference(s) of the selected object are flagged in the Comparison Summary section. The corresponding Diff1 or Diff2 colour is used to highlight for Change in Properties and Change in Position with the value as Yes. For additional information on comparing drawings, see Comparing Drawings.