Download Vertical Angles

Angle Pair
Relationships
Geometry
BCHS
I can:
• Identify vertical angles and linear pairs.
• Use vertical angles and linear pairs to
find measures of angles.
Which angles are adjacent?
1 &  2,  2 &  3,  3 &  4,
4&1
Then what do we call  1 &  3?
2
1
3
4
Vertical Angles – 2 angles
that are not adjacent and their
sides are formed by two
intersecting lines.
 1 &  3,  2 &  4
Linear Pair
(of angles)
• 2 adjacent angles whose noncommon sides are opposite rays
• They make a line!!!! 
Example
• Vertical angles?
1 & 4
• Adjacent angles?
2
1 & 2, 2 & 3,
1
3
3 & 4, 4 & 5, 5 & 1 5 4
• Linear pair?
5 & 4, 1 & 5
• Adjacent angles not a linear pair?
1 & 2, 2 & 3, 3 & 4
Important Facts
Vertical Angles Theorem-Vertical Angles
are congruent.
Linear Pair Postulate-The sum of the
measures of the angles in a linear pair is
180o.
Example:
• If m 5=130o, find
m 3 = 130°
m 6 = 50°
m 4 = 50°
4
5
3
6
A
Example:
E
B
D
• Find x & y,
then find:
m ABE
m ABD
m DBC
m EBC
C
x=40
y=35
m ABE=125o
m ABD=55o
m  DBC=125o
m  EBC=55o