Creating regions  

You can convert a closed entity into a two-dimensional region. After you create a region, you can modify it using the various three-dimensional tools. For example, you can create a region from a square, and then extrude the square to create a three-dimensional cube.

You can create regions from closed entities, such as polylines, polygons, circles, ellipses, closed splines, and donuts.       

Creating regions typically has no visible effect on a drawing. However, if the original entity had a width or lineweight, that information is lost when you create the region.    

To create a region

   1   Do one of the following to choose Region ():

    On the ribbon, choose Draw 3D > Region (in Draw 3D Solids).

    On the menu, choose Draw > 3D Solids > Region.

    On the Draw 3D Solids toolbar, click the Region tool.

    Type region and then press Enter.

   2   Select the entities to create the region.

   3   Press Enter.

The command bar displays a message that describes how many regions were created.