Not sure this is possible. It might be in 2014 depending on what how you need the final entities to behave.
Joe see if this helps. it is from another post by Matt Lambard
You have to make the 3 lines one spline using FIT SPLINE don't forget to uncheck the closed spline check box.
then use Matt's points shown in the .doc
Alright what I had to do was, create the fit spline from the original 2 lines and the arc. Then I added the points as shown from Matt L. Then had to create another new sketch
and copy the existing spline using convert entities. Then use the split entities below.
once you add the points you should be able to use TOOLS-SKETCH TOOLS- & then SPLIT ENTITIES
Thanks Tom. This is what I was looking for.
Can this be done with an equation?????