How to convert 3D Part to 2D Part "DXF"

I have a part which I'd like to cut on a 3-axis milling machine. For that I need to take a top view of the part into a 2D sketch and then save it as DXF is that right?
I have a part which I'd like to cut on a 3-axis milling machine. For that I need to take a top view of the part into a 2D sketch and then save it as DXF is that right?