High term best represents the intersection of two walls next to each other in a room?

point
plane
angle
line

When two walls intersect, they form a line. This line runs up and down the corner of the room. 

Skew lines(segments) are lines(segments) in 3 dimensions that do not intersect the given segment and are not parallel to it.  ae, bf, eg, and fh are your skew segments.  i hope that : )