Transcript 1-2 Points, Lines and Planes

What did the acorn say after it grew up?
Gee, I’m a tree
Geo: Earth
metry: Measure
Definition:
A statement that explains the meaning of a word or
phrase
Format for notes: (Optional method)
Term
Definition
Example

Point




P
Line





Most basic building block of geometry
It has no size, only location
Notation: Capital Letter
A straight, continuous arrangement of infinitely many
points
Infinite length but no thickness
Extends forever in two directions
AB
Notation: Naming any two points on line with line symbol
above
B
A
Plane



Length and width but no thickness.
Like a flat surface that extends infinitely along its length
and width.
Notation: Script Capital Letter
P

Collinear


E
On the same line
Coplanar


F
P
R
D
Q
On the same plane
Line Segment (segment)
B

Two points called endpoints of the segment
and all the points between them that are
collinear with the two points.
A
Notation: AB or BA

Length:

AB or mAB
5 cm
Endpoints
AB  5
mAB  5
B
A

Congruent Segments





Midpoint

D
Two segments with the same lengths
C
Symbol: 
Notation:AB  CD or AB  CD or mAB  mCD
Marking figures
Midpoint
A point that divides the segment into
two congruent segments
O
M
N
MN  NO
Ray
A part of a line that begins at a
point and extends infinitely in
one direction.
Notation:DA
A
D
Opposite Rays
Two rays that share the same
endpoint and form a line.
Notation:
A
CA
and
CB
C
B
1. Name a line
3. Name a ray
2. Name a line segment
4. Name a midpoint
5. Name congruent
segments
K
A
D
B
L
F
M
C
N
Postulate 1-1
Through any two points there is exactly one line.
Line t passes through points A and B. Line t is the only
line that passes through both points.
B
A
Postulate 1-2
t
If two distinct lines intersect, then they intersect in exactly
one point.
A
AE and DB
B
C
intersect at point C.
D
E