Day 1 1.1 Points, Lines, and Planes.notebook
August 21, 2013
Please find your seat,
have out something to take notes with,
and turn in your signed syllabus sheet into the basket
1.1 Points, Lines, and Planes
NOTES:
Day 1 1.1 Points, Lines, and Planes.notebook
August 21, 2013
Algebra Reminder...Quadrants
II I
III IV
(0,0)
Undefined Terms: cannot be defined by
using other figures.
3 undefined terms make up the Basic Building Blocks of Geometry
1. poınts
2. lınes
3. planes
A
l
Q
P
B
Space: set of all points
R
Day 1 1.1 Points, Lines, and Planes.notebook
POINT
•
•
•
•
•
•
•
simplest form
has no size
only has location
represented by a dot
has zero dimensions
name it with a capital letter
represents an ordered pair
Example
P(2,4) LINE
•
•
•
•
•
straight, arrangement of points
has no beginning or end
goes on forever
has one dimension­­length
named by using ANY 2 points
ex AB or BA
Example
B
A
l
line l or AB August 21, 2013
Day 1 1.1 Points, Lines, and Planes.notebook
Example 2:
August 21, 2013
Name each of the following
lines in 2 different ways.
M
a.
A
C
B
b.
A
M
P
c.
l
PLANE
• flat surface­ no thickness
• extends infinitely in all
directions
• named by capital script or 3
noncollinear points in a plane
Examples:
Q
P
R
R
Plane PQR
Day 1 1.1 Points, Lines, and Planes.notebook
August 21, 2013
The prefix "co" means TOGETHER
Collinear: points are on the same line
Ex.
A
E
C R D
C and R are coplanar
A, D, E are colinear
**Any two points can be collinear because you can draw a line through them!
Noncollinear: points are not on the same line
**Must be 3 or more points!
Day 1 1.1 Points, Lines, and Planes.notebook
August 21, 2013
Coplanar: points are on the same ________
or...
lines are on the same__________
C
R
B
Ex.
C, R, & B are coplanar
As any two points are collinear,
any three points are coplanar!
Example 1:
U
M
R
S
T
a.) Are the points S,T,U collinear? no
b.) Are the points R,S,T coplanar? yes
c.) Do the points, R,T, U create a plane?
Day 1 1.1 Points, Lines, and Planes.notebook
August 21, 2013
Find 3 points that are:
*collinear
*noncollinear
*coplanar
*noncoplanar
RAY
• A line with a starting point, but no ending. • It looks like an arrow.
written as AB
A
B
Day 1 1.1 Points, Lines, and Planes.notebook
August 21, 2013
LINE SEGMENT
B
A line that has both a start and end point.
written as AB or
l
l
A
Intersection:
• Where two planes or lines meet.
• Two lines intersect at a point.
• Two planes intersect at a line.
Spaghetti Junction, Atlanta, GA
Day 1 1.1 Points, Lines, and Planes.notebook
August 21, 2013
Keep in mind...
• You need two points to describe a line.
• You need three points to describe a plane.
notation review:
Points A, B, C
line l
AB, BA
Segment
AB, BA
`
Ray AB, BA (starts at A, points upward)
Ray BA, AB (starts at B, points downward)
C
B
l
A
Day 1 1.1 Points, Lines, and Planes.notebook
Classwork:
• Points, Lines, and Planes
August 21, 2013