To Align the UCS Dynamically With a 3D Solid

1. Start a command supported by dynamic UCS.
2. If necessary, click the Dynamic UCS button on the status bar or press F6 to turn it on.
   Note: Dynamic UCS is not displayed by default on the status bar. Click Customize on the status bar and select Dynamic UCS to display it.
3. Move your cursor over a planar face on a 3D solid.
4. Complete the command.