Transcript 1.1 Building Blocks of Geometry

7/21/2015
Chapter 1.1
Vocabulary
point
• line
• collinear points
• plane
• compass
• straightedge
• sketch
• draw
• construct
•
•
•
•
•
•
•
coplanar lines
skew lines
ray
endpoint of a ray
line segment
endpoints of a line segment
congruent line segments
Basic Geometric Figures
Undefined terms:
♥ Point
♥ Line
♥ Plane
X
B
M
A
Point
y
• Location shown by dots, can be
endpoints or corners
HOW TO WRITE:
ONE Capital Printed letter such as A
or X
W
Z
X
Y
Examples of Points
Is B on MY?
Lines
X
B
M
A
y
• All points arranged perfectly straight
with no thickness, and has infinite
length.
HOW TO WRITE:
AM MX XA
• two points on the line, with a doubleheaded arrow over the two letters.
• a single Lowercase Cursive letter.
y
t
Examples of Lines
Intersection
example: AB
U
U
• Symbol
D
A
X
C
B
CD = X
Book P.4-5
Plane
• A plane is a flat surface that extends
infinitely in all directions.
HOW TO WRITE:
♥ named by three non-collinear points that
ABC
lie on the plane
Or
♥ It can be named by one Cursive Capital
letter such as D.
B
A
D
C
S
Examples of Planes
Book p 7
Collinear
A
B
C
D
♥ Points on the same line
B
A
Coplanar
♥ Points on the same plane
C
Ray
♥ part of a line that starts at a point
and goes forever in one direction.
♥ HOW TO WRITE: Letter under
endpoint must be the start of the
ray.
B
A
BA
Segment
• a part of a line that begins at one point
and ends at another (the endpoints)
• HOW TO WRITE:
– The endpoints have a bar over them.
C
BA
A
CD
B
D
Book p.11-15
A
B
Hatch Marks – short slash markings that
show two or more segments are equal in
length
Urkle
Stephon
W
X
~
WX = YZ
Zack
Y
Z
Cody
Congruent - segments that have the same
measure (like equal)
Show what you know!