yes
yes they are same.
If you mean CD plus DC then in Roman numerals they add up to M meaning 400 plus 600 = 1000
CD and DC
yes
No. Line CD is the same as line DC, but rays are always named from the origin point, so ray DC is a ray pointing in the opposite direction from ray CD.
No, they are different!
yes
yes they are same.
Ab and Ba are the same line because there are no endpoints to a line. Therefore, you can reverse the order of the letters. So, Cd and Dc are not the same ray because the first letter is the endpoint. So on ray Cd, point C is the endpoint and d is a point on the line coming from the endpoint. On ray Dc, D is the endpoint.
They define the same line segment, connecting two points.
cd rs
If you mean CD plus DC then in Roman numerals they add up to M meaning 400 plus 600 = 1000
yes
NO
Yes
Yes