Convert any curve into a set of arcs with Convert to Arcs tool
Updated
Select Derive Segment tool and click on bottom edge of wall.
Observe a spline curve is derived.
Select Convert To Arc tool and click on spline curve.
Observe a set of arcs is derived.
Note: in Tool Options palette you can control the conversion as follows:
Maximum Deviation controls the approximation of the conversion. A smaller value creates more arcs and approximates the curve closer to original shape. A larger value creates less arcs and may deviate slightly from original shape.
Turn Make Composite ON to automatically join all the arcs into a single curve or turn this OFF to create the arcs as separate entities.