Each shape has its own tab on the Inspector on which you can set properties.

All shape objects have an anti-aliasing property that you can configure. Anti-aliasing smooths the appearance of jagged lines between solid colors. Objects that have curves or diagonal lines might also have jagged edges or lines.

Rounded rectangles and elliptical arcs have properties that you can configure to control the shape of those objects.

• Smooth a shape’s edges
  
• Change the roundness of a rounded rectangle object
  
• Change the shape properties of an elliptical arc