To modify the width of a form

Select (Modify Form).
Click Modify the Width of a Form icon.
From the Mode option menu, select Relative or Absolute.
Complete these settings:
For Absolute mode, enter the Thickness for the total width of the form.
For Relative mode, enter the Distance to increase/decrease the width.
Select a linear form width to modify.

Original form.

Center form segment after modifying the width 2 feet.