Creating a workplane aligned with average normal

1. Click Workplane tab > Create panel > Average Normal to display the Align with average normal dialog:

   

2. Select the Origin option, and click in the graphics window to specify the origin of the workplane.
3. Select the Selection option, and click the axis you want to align to the average normal of.
4. Select the Surface area option to prioritize the surface area of the surfaces in the selection, over the total number of surfaces.

   In the following example, there are 2 large surfaces and three minor surfaces in the selection.

   If Surface area is selected, the average normal of the selection is indicated by .

   If Surface area is deselected, the average normal of the selection is indicated by .

   

5. Click OK to create the workplane.