You can change the rounding radius of squares.
Procedure
Double-click a placed square. The property dialog opens.
Click Square on the Selection tab.
Move the slider to the required value on the scale. The value is output. Alternatively, you can either click the arrows or enter the value directly to change it.
Enable the Constant rounding check box if you do not want the rounding to be changed if the size of the symbol is subsequently changed in ARIS.
Click Preview to view your changes.
Click OK to apply your changes.
The rounding radius was changed according to your settings.