AT - draw a rectangle that is 18 x 6, and then use the top-left corner as your ellipse starting point, then bottom right as your 2nd click. Then, it gets a little messy... To cut in half, you'll need to explode the ellipse (3d Menus - Explode - into lines) and then erase the half you don't want. I hope that DCADv12 will allow us to work with ellipse like 1/2 rounds and other arcs.
-rd