Lesson 1 Notes

A point gives an exact location.  It has no length, width, or thickness.  We represent it with a dot.

We call this "point P."

A line consists of all the points that extend infinitely in two opposite directions.  It has no width or thickness but infinite length.

We call this "line MN" or "line l."

A ray is part of a line that contains one endpoint and all the points extending in one direction from the endpoint.  

We call this "ray MN."

A segment consists of two endpoints on a line and all the points between the endpoints.

We call this "segment MN."

A plane consists of all points on a flat surface.  It goes on forever all directions in two-dimensions.

For other definitions, click here.