Bellringer
• Name the plane represented by each surface of the box.
1. the bottom
2. the top
3. the front
4. the back
5. the left side
6. the right side
1.3
SEGMENTS, RAYS, PARALLEL LINES AND PLANES
Segments and Rays
• Def: Segment – the part of a line consisting of two endpoints and all points
between them.
• Def: Ray – the part of a line consisting of one endpoint and all the points of
the line on one side of the endpoint.
• Def: Opposite Rays – two collinear rays with the same endpoint. Opposite
rays always form a line.
Naming Segments and Rays
• Name the segments and rays in the figure.
A
Segments
Rays
1. 𝐴𝐵
1. 𝐵𝐴
2. 𝐵𝐶
2. 𝐵𝐶
3. 𝐴𝐶
3. 𝐴𝐶
B
C
Parallel Lines and Skew Lines
• Def: Parallel Lines (∥) – coplanar lines that do not
intersect
• Def: Skew Lines – noncoplanar lines; therefore, they are
not parallel and do not intersect
Name Parallel and Skew Lines
Name 3 sets of Parallel Lines
Name 3 sets of Skew Lines
1. 𝐴𝐵 ∥ 𝐷𝐶
1. 𝐴𝐵 and 𝐶𝐺
2. 𝐴𝐸 ∥ 𝐷𝐻
2. 𝐸𝐻 and 𝐵𝐹
3. 𝐸𝐹 ∥ 𝐻𝐺
3. 𝐷𝐻 and 𝐹𝐺
Parallel Planes
• Def: Parallel Planes – are planes that do not intersect.
• Plane ABCD ∥ Plane EFGH
• Name another set of Parallel Planes
Plane ADHE ∥ Plane BCGF
Identifying Parallel Planes
Use the diagram to name the
figures
1.Three pairs of parallel planes
2. A line that is parallel to 𝐸𝐺
3. A line that is parallel to plane
FGCB
Ticket Out the Door
• How are parallel and skew lines alike? How are
they different?
Homework
• Pg. 19 #’s 1 – 7; #’s 11 – 20; #’s 21 - 24