Download 1.1 Getting Started

1.1 Getting Started
Terms to know!
Points
• A specific place in space
• Labeled by a capital letter

A

B

C
Lines
• Two points connected with a straight line
• Made up of many points (must have 2 points
to determine a line)
• Contains arrows at both ends
• Goes on into infinity
• Labeled by a lower case letter or by 2 points
A
AB
m
B
Give all possible names for
line l
l
A
B
C
D
Line Segment
• Made up of 2 points on a number line
but has a beginning and an end
• Labeled by the two end points in either
direction
• Symbol does not have arrows at the
end
X
XY
Y
YX
A
-1
B
C
D
E
F
0
1
2
3
4
• On the number line, name the line
segment for the section between 1 and
3
• Between 0 and -1
• Between 2 and 4
• Between -1 and 3
Ray
• Made of points
• Has a beginning point but no end point
• Named by the beginning point then any
other point
• Goes on forever in one direction
A
B
C
AB
or
AC
Angle
•Two rays with a common end point
•Vertex: name of the common point
A
B
1
C
<B
<ABC
<1
•Sides formed by the rays
•Named by numbers or letters
•Middle letter is always the vertex
•Can be named by vertex when only
one angle present
Name all of the angles below:
A
B
1
D
2
C
∆Triangle
•A triangle has 3 segments as its
sides
B
X
•A triangle has 3 angles
O•Written
as
BOX
•A triangle is the union of three
segments (symbol: U )
BOX = BO U OX U XB
Intersection 
The intersection of any two
sides is the vertex.
C
A
T
CAT
CA  AT = A