Points, Segments, Lines, Angles, and Planes
Vocabulary Points Lines Planes Parallel/Perpendicular Collinear/Coplanar Skew Lines
Point A point is like a dot, and is named by one letter. Tip of a pencil M
Line A line is an infinite set of points that expand in both directions. n A B Pretend this road extends forever.
Line Segment A line segment is part of a line, defined by two endpoints. C D
Ray A ray is part of a line with one endpoint. It extends infinitely in one direction. C D Sun Ray
Plane A plane is the set of all points that form a flat surface. It extends in all directions infinitely.
Intersecting Lines Two or more lines that meet at a point. F
Parallel Lines Two or more lines that never intersect.
Perpendicular Lines Two lines that intersect and form RIGHT angles.
Collinear Points are points that lie on the same line.
Coplanar Points are points that lie on the same plane
Planes intersect at a line. Skew lines are lines that do not intersect, are not parallel, and do not lie in the same plane.
A Line and Plane Intersecting
In Summary Planes intersect at a line Lines intersect at a point A line and a plane intersect at a point Skew lines are not parallel, do not intersect, and are not on the same plane