View triad

A triad that displays the orientation of the global coordinate system axes. It appears in the lower left corner of each view window. As you move the view of a window, the triad displays the changes to the coordinate system orientation.

To toggle its display:

On the Main toolbox, from the Toggle Tool Stack, click the View Triad tool .
Double-click to apply the change to all view windows. The tool must be on top of the tool stack to double-click it.