1.2 Points, Lines, and Planes

1.2 Points, 1.2 Points, Lines, and Lines, and

PlanesPlanesObjective:

Understand and use the basic

terms and postulates of

geometry.

1.2 Vocabulary

– Point– Line– Plane– Collinear Points– Coplanar– Space

– Segment– Ray – Opposite Rays– Postulate– Axiom– Intersection

Remember y = mx + b ?

Vocab Terms:

Vocab Terms:

Or plane ABC

Or BA

or line l

Naming Points, Lines, and Planes

•How can you tell that the label P is naming a plane instead of a point?•Why is plane RQS not a valid name for the plane?•What point(s) do lines l and m have in common?

Compare and Contrast• How is naming a ray similar to naming a

line? How is it different?

Naming Segments and Rays

Can the three points shown on the line be used to name a plane? Explain.

Vocab Terms:

• Intersection: set of points the figures have in common

• Postulate or axiom: an accepted statement of fact

Postulate 1-1

Postulate 1-2

Postulate 1-3

Postulate 1-4

You Know How?