in the Tools toolbar.Rulers are useful when measuring a distance or getting a general overview of the dimensions in the view. They also help to position elements precisely. When visible, rulers appear along the top and left side of the active 2D window. Red markers in the ruler display the pointer’s position when moving an object.
1. Click Rulers in the Tools toolbar.
2. Rulers are displayed at the top and the left hand side of the 2D view.
3. Click Rulers once more to hide the rulers again.
Note
The unit of measurement used in these rulers is mm.