Upload
smily-hemanth
View
48
Download
1
Tags:
Embed Size (px)
Citation preview
LINES AND ANGLES
PARALLEL LINES
Def : line that do not intersect.
Illustration:
Notation: l || m AB || CD
lm
A
B
C
D
p. 129
Examples of Parallel Lines• Streets: Home & School
Def: Lines that intersect to form a right angle.
Illustration:
Notation: m n
Key Fact: 4 right angles are formed.
PERPENDICULAR LINES
m
n
p. 79
Transversal
Def : a line that intersects two lines at different points
Illustration:
t
Vertical Angles
Two angles that are opposite angles.
1 2
3 4
5 6
7 8
t
Ð1 4Ð2 3Ð5 8Ð6 7
SUPPLEMENTARY ANGLES/LINEAR PAIR
• Two angles that form a line (sum=180)
1 2
3 4
5 6
7 8
tÐ5+6=180Ð6+8=180Ð8+7=180Ð7+5=180
Ð1+2=180Ð2+4=180Ð4+3=180Ð3+1=180
CORRESPONDING ANGLES
Two angles that occupy corresponding positions.
Top Left
t
Top Left
Top Right
Top Right
Bottom Right
Bottom Right
Bottom Left
Bottom Left
Ð1 5Ð2 6Ð3 7Ð4 8
1 2
3 4
5 6
7 8
Alternate Interior AnglesTwo angles that lie between parallel lines on
opposite sides of the transversal
t
Ð3 6Ð4 5
1 2
3 4
5 6
7 8
Alternate Interior AnglesFind the measures of the missing angles
82
?
t
98 82
ALTERNATE EXTERIOR ANGLES Two angles that lie outside parallel lines on
opposite sides of the transversal
t
Ð2 7Ð1 8
1 2
3 4
5 6
7 8
Find the measures of the missing angles
Alternate Exterior Angles
120
?
t
60 120
Consecutive Interior Angles• Two angles that lie between parallel lines on the
same sides of the transversal
t
Ð3 +5 = 180Ð4 +6 = 180
1 2
3 4
5 6
7 8
p. 131 & 143
B Y H E M A N T H YO S H I K A