The Object Inspector is located along the left-hand side of the interface, to the left of the graphic editor. You can resize its width or close it to allow for more working space in the graphic editor. To close the Object Inspector, select Window > Inspector Dialog Box or click the in the toolbar.
The Object Inspector:
The Object Inspector consists of several topic-specific elements. Tabs to select these topics are along the bottom of the dialog.
Object Inspector (tabs: Geometry and Groups)