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

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.

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.

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.

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.

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

Classwork/Homework Pg 17 #s 2-34 even