Create a cross section of seating. (fixed sectional)
Create a curved line sweep the sofa section shape.
Align the section shape of the seating perpendicular to the curved line. (Use the perpendicular to curve line tool.) Move the section shape to the end point of the curve line. Then rotate the section shape to match the curved line.
Sweep the section along the edge of the curved line.
Cap the end of the curved seating.
