1. 1.1 Understanding Points, Lines, and Planes

2. Understanding Points, Lines, and Planes
Undefined terms- words that cannot be defined by using other figures
Point- has no size or dimension; names a location
Line- straight path that has no thickness, extends forever in two directions
Plane- flat surface that has no thickness, extends forever in two dimensions

3. Collinear- 3 or more points on the same line
Coplanar- 3 or more points on the same plane

4. Segment (line segment) – part of a line, contains two points and all of the points between them
Endpoint- points on the end of a segment or the starting point on a ray

5. Ray- part of a line, starts at an endpoint and extends forever in one direction
Opposite ray- two rays that have a common endpoint and extend in opposite directions forming a line

6. Examples: a) Name 3 different segments b) Name the line 2 ways
c) Name 4 different rays
Add 3 points to the line.

7. Examples: a) Name 4 points that are coplanar
b) Name 4 points that are not coplanar
c) Name 3 points that are collinear
Add a plane with two intersecting lines

8. Potulates (1.1.1) Two points determine a line
(1.1.2) Three noncollinear points determine a plane
(1.1.3) If two points are in a plane, then the line containing the points is also in the plane

9. (1.1.4) Two lines intersect at exactly one point
(1.1.5) Two planes intersect at exactly one line

10. Examples: 3) Sketch two lines intersecting at exactly one point
4) Sketch two lines intersecting a plane at two points