Mathematical Properties of Surfaces
You can define the mathematical properties of a surface when you create some surfaces. You can also set these properties on the Modify Shape tab or in the 
Mathematical Properties dialog box. When you change the mathematical properties of surfaces, you can expect the following results:
Mathematical Properties dialog box. When you change the mathematical properties of surfaces, you can expect the following results:• As the number of segments or degree increases, you have more control points and can manipulate the surface more easily. Such surfaces closely follow the facet data and can be fitted to the facet data with more accuracy.
• Fewer segments or a lower degree setting makes the surface more rigid because of fewer control points. Such surfaces appear smoother and are better from a manufacturing point of view.
• Your last input for the type of surface and its settings, becomes the default for creating the next surface.