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5. 6. 4. 7. 8. 3. 2. t. 1. Warm up. List all pairs of angles that fit the description. Corresponding Alternate Interior Alternate Exterior Consecutive Interior. LINES AND ANGLES. B. A. D. l. C. m. 28. PARALLEL LINES. Def: line that do not intersect. Illustration:
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5 6 4 7 8 3 2 t 1 Warm up List all pairs of angles that fit the description. • Corresponding • Alternate Interior • Alternate Exterior • Consecutive Interior
B A D l C m 28 PARALLEL LINES • Def: line that do not intersect. • Illustration: • Notation:l || mAB|| CD p. 129
Examples of Parallel Lines • Hardwood Floor • Opposite sides of windows, desks, etc. • Parking slots in parking lot • Parallel Parking • Streets: Laramie & LeClaire
Examples of Parallel Lines • Streets: Belmont & School
m n 29 PERPENDICULAR LINES • Def: Lines that intersect to form a right angle. • Illustration: • Notation:m n • Key Fact: 4 right angles are formed. p. 79
Ex. of Perpendicular Lines • Window panes • Streets: Belmont and Cicero
30 Transversal • Def: a line that intersects two lines at different points • Illustration: t p. 131
Vertical Angles • Two angles that are opposite angles. t • 14 • 2 3 • 5 8 • 6 7 1 2 4 3 6 5 7 8
Vertical Angles • Find the measures of the missing angles t 125 ? 125 55 ? 55
t 1 2 4 3 6 5 7 8 Supplementary Angles/Linear Pair • Two angles that form a line (sum=180) • 1+2=180 • 2+4=180 • 4+3=180 • 3+1=180 • 5+6=180 • 6+8=180 • 8+7=180 • 7+5=180
Supplementary Angles/Linear Pair • Find the measures of the missing angles t ? 108 72 180 - 72 ? 108
1 2 3 4 5 6 7 8 30 Corresponding Angles • Two angles that occupy corresponding positions. t • 15 • 2 6 • 3 7 • 4 8 Top Left Top Right Bottom Left Bottom Right Top Left Top Right Bottom Left Bottom Right p. 131 & 143
Corresponding Angles • Find the measures of the missing angles t 145 35 ? 145
30 Alternate Interior Angles • Two angles that lie between parallel lines on opposite sides of the transversal t • 3 6 • 4 5 1 2 3 4 5 6 7 8 p. 131 & 143
Alternate InteriorAngles • Find the measures of the missing angles t 82 82 98 ?
30 Alternate Exterior Angles • Two angles that lie outside parallel lines on opposite sides of the transversal t • 2 7 • 1 8 1 2 3 4 5 6 7 8 p. 131 & 143
Alternate ExteriorAngles • Find the measures of the missing angles t 120 ? 120 60
30 Consecutive Interior Angles • Two angles that lie between parallel lines on the same sides of the transversal t • 3 +5 = 180 • 4 +6 = 180 1 2 3 4 5 6 7 8 p. 131 & 143
Consecutive InteriorAngles • Find the measures of the missing angles t 180 - 135 135 45 ?
Corresponding 4 and 2 3 and 1 5 and 7 6 and 8 5 6 4 7 8 3 2 t 1
Alternate Interior 3 and 7 2 and 6 5 6 4 7 8 3 2 t 1
Alternate Exterior 5 and 1 4 and 8 5 6 4 7 8 3 2 t 1
Consecutive Interior 5 3 and 2 6 and 7 6 4 7 8 3 2 t 1
Find all angle measures t 180 - 67 113 67 1 3 67 2 113 113 5 67 8 67 6 7 113
LINES AND ANGLES Part II: Equations
Alternate Exterior Angles • Name the angle relationship • Are they congruent or supplementary? • Find the value of x t 5x = 125 125 5 5 x = 25 5x
Corresponding Angles • Name the angle relationship • Are they congruent or supplementary? • Find the value of x t 2x + 1 = 151 - 1 - 1 2x + 1 2x = 150 2 2 151 x = 75
Consecutive Interior Angles • Name the angle relationship • Are they congruent or supplementary? • Find the value of x supp t 7x + 15 + 81 = 180 7x + 96 = 180 - 96 - 96 81 7x = 84 7x + 15 7 7 x = 12
Alternate Interior Angles • Name the angle relationship • Are they congruent or supplementary? • Find the value of x t 2x + 20 = 3x - 2x - 2x 3x 20 = x 2x + 20