Editing a 2point arc

I would like to know how I can simply edit a 2 point arc. I would like to simply extend or lengthen both end points and still maintain the same curve.

It depends on exactly what the situation is but you could use Rotate/Copy to copy the arc. Or it might be easier or more practical to locate the center of the arc, delete the arc, and redraw it to the desired length. It would help if you share more detail about what you are trying to acomplish.