Line
A line is infinitely long, in space it is defined by two points. Any three different points on the line will form 180° angle.
Ray
A ray, is a subset of a line, it begins at one point and extends indefinitely in one direction.
Line Segment
A line segment is a subset of a line; it begins at one point and ends at another.
Transversal
If two distinct lines are intersected by a third line (not at the same point), then the third line is called transversal of the other two lines.
Midpoint
Midpoint divides a line segment into two congruent sub segments.
