1. Bellwork # 3 Judging by appearances, will the lines intersect? 1. 2.3.
Name the plane represented by each surface of the box.
4. The bottom
7. The top
5. The front
8. The back
6. The left side
9. The right side

2. Segments, Rays, and Parallel Lines
Unit 1.2 Notes
Segments, Rays, and Parallel Lines

3. Opposite rays Ray Parallel lines Segment Parallel planes Skew lines
1.2 Vocabulary
Copy the following vocabulary words on your paper.
Opposite rays
Ray
Parallel lines
Segment
Parallel planes
Skew lines

4. Segment
Definition: The part of a line consisting of two endpoints and all points between them. A B AB
Read “segment AB”

5. Ray
Definition: The part of a line consisting of one endpoint and all the points of the line on one side of the endpoint. X Y XY
Read “ray XY”

6. Opposite Rays Definition: Two collinear rays with the same endpoint. Q
RQ and RS are opposite rays.
Opposite rays always form a line.

7. Q P L
Name the segments and rays in the above figure.
The three segments are LP, PQ, and LQ.
The four rays are LP or LQ, PQ, PL, and QP or QL

8. Parallel Lines
Definition: Coplanar lines that do not intersect.
AB EF

9. Skew Lines Definition: Noncoplanar lines that do not intersect.
These lines do not actually intersect – they are not on the same plane. However, they are also, not parallel lines.

10. Parallel Planes Definition: Planes that do not intersect. ABE DCG
Plane ABCD GH
A line and a plane that do not intersect are also parallel.