Points, Lines, and Planes

Point

• a dot

• no size

• only location

Line • a straight line that goes on forever in both

directions

• can use any 2 points to name a line

• symbolized by

Collinear• points on the same line

Plane• a flat surface

• no thickness

Coplanar• points that are on the same plane

WHAT ARE THE UNDEFINED TERMS IN GEOMETRY?

point

line

plane

line segment• line that has endpoints (does not go on

forever

• symbolized by

Intersection of 2 Lines

• Is always a point

Intersection of two Planes

• Is always a line

Ray

•has 1 endpoint

•symbolized by

Opposite Rays

• two rays that have the same endpoint and go in opposite directions

Summary

• What does collinear mean?

• What does coplanar mean?

• What are the symbols for line, ray, and line segment?