A ray is a subset of a line which has one endpoint and extends only in one direction. and the segment is the subsets of a line that have 2 endpoints.. == Hey. I just learned that.
http://wiki.answers.com/Q/What_are_the_subsets_of_...

A ray is a subset of a line which has one endpoint and extends only in one direction. The segment is the subsets of a line that have 2 endpoints. Each point on the line, any set of
http://www.fixya.com/support/t9437374subsets

infinety of sub set
http://answers.yahoo.com/question/index?qid=200906...
