Two collinear rays with the same endpoint
Opposite Rays
noncoplanar - they are not parallel and do not intersect
Skew Lines
Coplanar lines that do not intersect
Parallel Lines
Planes that do not intersect
Parallel Planes
The part of a line consisting of two endpoints and all points between them
Segment
The part of a line consisting of one endpoint and all the points of the line on one side of the endpoint
Ray