a. Line CR.
Remember that a line is infinite, it has no endpoints. The image below shows a representation of this line.
The arrows indicate that the line extends infinitely.
b. Ray BP.
A ray is half a line, that is, it has one endpoint and one infinite extend.
c. Segment AE.
A segment is a portion of a line, it has two endpoints, it's not infinite.
There you have it, each representation with the proper notation.
