Section 1-3: Segments, Rays, Parallel Lines, Planes SPI 32A: Identify properties of plane figures...
10
Section 1-3: Segments, Rays, Parallel Lines, Planes SPI 32A: Identify properties of plane figures bjectives: • Identify segments and rays • Recognize parallel lines Point: Designates a location, has no size, named by a capital letter Line: Series of points that extends in 2 opposite direction without end Space : A set of all points. Plane : Flat surface with no thickness; contains many lines Collinear Points: Points that lie on the same
-
Upload
dale-stevens -
Category
Documents
-
view
217 -
download
0
Transcript of Section 1-3: Segments, Rays, Parallel Lines, Planes SPI 32A: Identify properties of plane figures...
Section 1-3: Segments, Rays, Parallel Lines, Planes SPI 32A: Identify properties of plane figures
Objectives:• Identify segments and rays• Recognize parallel lines
Point: Designates a location, has no size, named by a capital letter
Line: Series of points that extends in 2 opposite direction without end
Space: A set of all points.
Plane: Flat surface with no thickness; contains many lines
Collinear Points: Points that lie on the same line
How to sketch:
How to name:
AB
AB or BA
The symbol AB is read as "segment AB".
Segment:
Definition: Part of a line consisting of two endpoints and all points in between. (Segment AB or BA)
AB
Ray:
Definition: Part of a line consisting of one endpoint and all the points of the line on one side of the endpoint. When naming, endpoint must be listed first. (AB and BA are not the same)
AB��������������
( the symbol RA is read as “ray RA” )
How to sketch:
How to name:
R
AR A Y
RA ( not AR ) RA or RY ( not RAY )
( Opposite rays must have the same “endpoint” )
AX Y
D ED E
opposite rays
DE and ED are not opposite rays.
Opposite Rays:
Definition: Two collinear rays with the same endpoint. Opposite rays always form a line.
Name the segments and rays in the figure.
A segment is a part of a line consisting of two endpoints and all points between them. A segment is named by its two endpoints. So the segments are BA (or AB) and BC (or CB).
A ray is a part of a line consisting of one endpoint and all the points of the line on one side of that endpoint. A ray is named by its endpoint first, followed by any other point on the ray. So the rays areBA and BC.
Naming Segments and Rays
Vocabulary (cont)
Parallel Lines:
Definition: Coplanar lines that do not intersect
Skew lines:
Definition: Noncoplanar (they do not lie in the same flat surface), therefore they are not parallel and do not intersect.
AB CD
Parallel Planes:
Definition: Planes that do not intersect.
Plane KLQP II plane NMRSPlane KLMN II plane PQRSPlane PKNS II plane QLMR
Use the figure below. Name all segments that are parallel to
AE. Name all segments that are skew to AE.
Parallel segments lie in the same plane, and the lines that contain them do not intersect. The three segments in the figure above that are parallel to AE are BF, CG, and DH.
Skew lines are lines that do not lie in the same plane. The four lines in the figure that do not lie in the same plane as AE are BC, CD, FG, and GH.
Naming Parallel and Skew Lines
Perpendicular Lines:
Midpoint:
Definition: Lines which intersect to form a right angle (90°)
AB CD
Definition: Divides a line segment into two congruent (equal) segments.
B
A
DC
AC Segment with midpoint B.
Intersect:
Definition: Crossing or sharing a point
Vocabulary (cont)
A B C
Enrichment 1-3
A street map can be thought of as a series of parallel, intersecting, and skew segments.
Name a street that is parallel to Park Street.
Name a street that intersects State Street.
Name a street that intersects Hemlock Avenue.
Will a car traveling on Hill Street ever meet a car traveling on Crosstown Road? Explain.
Name all streets on the map that are parallel to State Street.
