1. What’s on the Menu Today?
Daily Warm Up
Turn in and go over homework questions
1.2 Notes on Basic Geometric Terms
Basic Definitions Work Sheet

2. Warm It Up #1
Using what you learned about the Three Steps to Reason, make a conjecture about the first 100 positive even integers.
Share your conjecture with a friend. Do you think this conjecture is valid? If so, why? If not, why not?
2 is the only prime number in the first 100 positive even integers
The last number is actually 200 since there are 50 evens in the first 100 and 50 evens in the second.

3. Section 1.2: Basic Geometric Terms
Identifying Geometric Terms in Real Life
Section 1.2: Basic Geometric Terms

4. Definition: Point
A point has no dimension and is usually represented by a small dot.
Point A . A

5. Definition: Line
A line extends without end in two directions. It is usually represented by a straight line with two arrowheads (symbolized by AB)
Collinear Points: two points that lie on the same line.
Example: A and B are collinear points

6. Definition: Line Segment
A Line Segment is the part of a line ending at two specific points and all the points between the two endpoints.
(Notice there are no arrows at the end) A B

7. Definition: Ray & Initial Point
The ray AB (symbolized by AB) consists of the initial point A and all points on AB that lie on the same side of A as point B.
IMPORTANT: the first letter must indicate the starting point of the ray.

8. Definition: Opposite Rays
Opposite Rays share a common initial point, but point opposite directions. If C is between A and B, then CA and CB are opposite rays.
Any two opposite rays are collinear. A C B

9. Recap Line Segment Ray Opposite Ray
Draw what they look like and how to denote them in the boxes

10. .
A plane extends in two
dimensions. It is usually
represented by a shape that
looks like a table or a wall,
however you must imagine that the plane extends without end

11. Definition: Coplanar Points
Coplanar points are points that lie on the same plane.
Call it: Plane M or plane ABC
Note: points A,B,C are coplanar points.
.A B
.C M

12. Definition: Intersect
Geometric figures are said to intersect if they have one or more points in common.
The intersection of the figures is the set of points the figures have in common.
How many points of intersection do these lines have in common?

13. Your Turn EX: Sketch a line that intersects a plane at one point.
Solution:
Draw a plane and a line
Emphasize the point
where they meet
Dashes show where
the line is hidden
by the plane.

14. Your Turn Ex: Sketch two planes whose intersections form a line.
Solution:
Draw two planes
Emphasize the line
where they meet.
Dashes indicate that one
plane is hidden by the other.

15. Intersecting “planes”

16. Homework
P. 13 # Odd,