2. Chapter 1-3 Points, Lines and Planes
Geometry
Chapter 1-3
Points, Lines and Planes

3. Why do chairs sometimes wobble?
What do the feet of a three legged stool represent?
Points that lie in the same plane.
Why does a four legged chair sometimes wobble on a flat surface?
One of the legs represents a point that doesn’t lie in the same plane as the other 3.

4. Key Terms A point is simply a location
A line is made up of points that has no thickness or width.
Points that are on the same line are said to be collinear.

7. Terms cont… A plane is a flat surface made up of points.
Points that lie on the same plane are said to be coplanar.
A plane has no depth and extends infinitely in all directions.
Points are often used to name lines and planes.

11. Postulates
You need two points to describe a line, and three noncollinear point to describe a plane.
Postulates are statements that are accepted without further justification.

12. Finally Line segments consists of endpoints
A ray has and endpoint and a side that continues forever.

13. Classwork/Homework
Pg 17 #s 2-34 even