With the Wall Tool selected, choose the Rectangle Wall method from the Info Box. (Pop out the small black arrow on the Straight Wall Method button.)
Draw the diagonal of the rectangular wall and click to define its length. The rectangle wall is created.
Its four sides are always aligned orthogonally with the Normal Grid and are not affected by the use of a Rotated Grid.
The Rotated Rectangle Wall method produces four wall elements as with the previous method, except that you first define a rotation vector for the rectangle’s base reference line. Then drag the cursor to define the rectangle.