1. On whiteboard draw the guided practice diagram shown on pg. 7
Reference this diagram as you discuss the terms

2. 1.2 Points, Lines, and Planes

3. There are three undefined terms in geometry:
What is a definition?
Known words used to describe a new word
Undefined terms – are terms not formally defined.
There are three undefined terms in geometry:
1. Point 2. Line 3. Plane

4. Point 1. A location in space.
2. Has no dimension (no length, no width, no depth).
3. All geometric figures consist of points
POINTS ARE TO GEOMETRIC FIGURES AS ___________ IS TO HUMANS?

5. What would be a real world example of a point?
For example: ●B
What would be a real world example of a point?

6. Line
An infinite set of points that extends in opposite directions forever.
One-dimensional (length).
Always straight.

7. How do we name a line has more than 2 points on it?
For example:
Can be called:
Line l
Line AB or AB
Line BA or BA l A B
Real World example?
How do we name a line has more than 2 points on it?

8. Plane
A flat surface that extends forever in two dimensions (length & width).
Contains infinitely many points and lines.
Has no thickness

9. Plane For example: Can be named: Plane W
Plane ABC, plane BCA, plane CBA, etc.
**Planes can be named by more than 3 points, but they must be named in either a clockwise or counter-clockwise manner A W C B
Real World example?

10. Horizontal Planes – Ceiling and Floor
Horizontal Planes – Two sides horizontal and no sides vertical 10

11. Vertical Planes – Walls Vertical Planes – two sides are vertical11

12. **Think of the preffix “CO” as sharing.**
More Definitions
Collinear points –
points that can lie on the same line.
**Think of the preffix “CO” as sharing.**

13. More Definitions
Noncollinear points – D

14. More Definitions Coplanar points – What does it mean?
points that can lie on the same plane.

15. More Definitions If the points do not lie in the same plane they are?
Noncoplanar points – A D

16. QUESTIONS 1 – 10 ON WORKSHEET16

17. More Definitions Intersect – Intersection –
Two or more figures intersect if they have one or more points in common.
Think “meet” or “Cut”
Intersection –
All points or sets of points the figures have in common.
Depending on what is intersecting, the intersection will be different

18. 4 types of intersections between points, lines, and planes
Point and a line
2 lines
2 planes
A plane and a line

19. When a line and a point intersect, their intersection is a point.B
Like taking a road trip and driving through a certain town or city on the map.

20. When 2 lines intersect, their intersection is a point.
Like the intersection of Foothill and Ramsdale

21. When 2 planes intersect, their intersection is a line.
The planes are cutting through one another

22. When a line and plane intersect, their intersection is a point.
Like sticking a pencil through a piece of paper

23. QUESTIONS

24. More Definitions
Equidistant – equally distant

25. TRUE/FALSE
PF ends at P
A plane has no thickness
REST OF QUESTIONS

26. Questions???