How to select a face in a 3D solid without turning around

[vindicate]

Hi. I was hoping to find an answer here how can I put a circle or a line on the bottom of the object below without rotating the view. I tried to point the cursor but the top face is always blocking it. I also selected the UCS control as Bottom but every time I point my cursor, it changes to Unnamed. I was hoping if there is a setting or something. I am new at autocad 3D. Please help me. I attach a picture for reference.

[Cad64]

One way to do this would be to draw a temporary construction line from endpoint to endpoint. Then you can draw a circle at the midpoint of that line and then delete the line.

Also, working in 2D wireframe mode, instead of Xray mode, makes it easier to work without the faces getting in the way.