Click Tangent
Arc 
(Sketch
toolbar), and add tangent arcs between each set of end points.
Click Tangent
Arc (Sketch
toolbar), and add tangent arcs between each set of end points.
Click Smart Dimension
(Dimensions/Relations
toolbar), and dimension one of the arcs to fully define the sketch.
Click Save
(Standard toolbar),
and save as 3d_loft.sldprt.
