Before scaling objects, you must activate Scaling mode. Scaling handles then appear on selected objects, which you can use for scaling.
To activate scaling mode in the Viewer window, do one of the following:
Depending on what you have selected in the Selection Mode Menu, Scaling handles appear on any selected object. If you select “Selection” you can drag the scaling handles to change the size of the object on any axis. The following figure displays the scaling handles of the selected object, enabling you to scale the object on each axis.

Scaling handles enables you to scale the object on each axis
Double-click a scaling handle and enter a value in the
Axis Scaling Factor Delta dialog box that appears.