Basic Geometry

Basic Geometry

A POINT is an exact location. D A

C

B E

• A line is a set of points that extends forever in two directions.

A B We name the line after points in it. This is how you write it

or

AB

BA

• A segment is like a line, except it has “endpoints”. It does not go on forever. C endpoint D

endpoint

We name the segment after its endpoints.

CD

or

DC

• A ray is like a line, but it goes in only one direction forever, and has only one “endpoint” endpoint

H

X When naming a ray you always say or write the “endpoint” FIRST!

HX

XH

• A plane is a flat surface that extends forever in two dimensions. They have no thickness.

A

• When two rays come