linesandangles2
TRANSCRIPT
PARALLEL LINES
• Def: line that do not intersect.
• Illustration:
• Notation: l || m AB || CD
lm
A
B
C
D
Examples of Parallel Lines• Hardwood Floor
• Opposite sides of windows, desks, etc.
• Parking slots in parking lot
• Parallel Parking
• Streets: Laramie & LeClaire
PERPENDICULAR LINES
• Def: Lines that intersect to form a right angle.
• Illustration:
• Notation: m n
• Key Fact: 4 right angles are formed.
m
n
Adjacent angles
Two angles are said to be adjacent angles if:1)They have a common vertex.2)They have a common arm.3)The non-common arms lie on either side of the common arms.
Supplementary Angles/Linear Pair
• Two angles that form a line (sum=180)
1 2
3 4
5 6
7 8
t
5+6=1806+8=1808+7=1807+5=180
1+2=1802+4=1804+3=1803+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
1 52 63 74 8
1 2
3 4
5 6
7 8
Alternate Interior Angles
• Two angles that lie between parallel lines on opposite sides of the transversal
t
3 64 5
1 2
3 4
5 6
7 8
Alternate Exterior Angles
• Two angles that lie outside parallel lines on opposite sides of the transversal
t
2 71 8
1 2
3 4
5 6
7 8
Consecutive Interior Angles
• Two angles that lie between parallel lines on the same sides of the transversal
t
3 +5 = 1804 +6 = 180
1 2
3 4
5 6
7 8