Need advise on a half circle carve

[kelsky]

As you can see the shape is an ARC with a connector line. But I want the carve to be a rounded up from the center of the line where I made a circle. Then curve upward from that point to the arc lines as indicated with the arrows.

I've tried various methods but can't seem to get it. The puffing circle is perfect except I only want a half circle.

Thx in advance for your input.

[bergerud]

I would try and use puffing on a full circle and then cover up the part you do not want.