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G E O M E T R Y. Math 7 Unit 4. Standards. GEOMETRY IS EVERYWHERE. IN FLAGS. IN NATURE. IN SPORTS. IN MUSIC. IN SCIENCE. IN Games. IN BUILDINGS. The hardest part about Geometry. Vocabulary. A. Point. : a location in space. : think about the tip of your pencil. Notation :. ●A.
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GEOMETRY Math 7 Unit 4
The hardest part about Geometry Vocabulary
A Point : a location in space : think about the tip of your pencil Notation : ●A
A B Line all the points on a never-ending straight path that extends in all directions Notation :
C D Segment all the points on a straight path between 2 points, including those endpoints Notation :
E F Ray a part of a line that starts at a point (endpoint) and extends forever in one direction Notation :
Side A 1 B C Side Vertex Angle formed by 2 rays that share the same endpoint. The point is called the VERTEX and the rays are called the sides. Angles are measure in degrees. 70
A 15° B C Angle Notation :
A Plane a flat surface without thickness extending in all directions Think: a wall, a floor, a sheet of paper Notation :
C A B D Parallel Lines lines that never intersect (meet) and are the same distance apart Notation : ║
D A B C Perpendicular Lines lines that meet to form right angles Notation :
D A B C Intersecting Lines lines that meet at a point
Right Angle An angle that measures 90 degrees.
Straight Angle An angle that measures 180 degrees or 0. (straight line)
Acute Angle An angle that measures between 1 and 89 degrees
Obtuse Angle An angle that measures between 91 and 179 degrees
2 1 Complementary Angles Two or more angles whose measures total 90 degrees.
2 1 Supplementary Angles Two or more angles that add up to 180 degrees.
*****Reminders****** Supplementary Straight angle Complimentary Corner
A D B C Adjacent Angles Two angles who share a common side
Example 1 • Estimate the measure of the angle, then use a protractor to find the measure of the angle.
2 60 1 Example 1 • Angles 1 and 2 are complementary. If • m 1 = 60, find m 2. 1 + 2 = 90 2 = 90 - 1 2 = 90 - 60 2 = 30
114 1 2 Example 3 • Angles 1 and 2 are supplementary. If m 1 is 114, find m 2. < 1 + < 2 = 180 < 2 = 180 - < 1 < 2 = 180 - 114 < 2 = 66
7.2 Angle Relationships t 1 2 4 3 6 5 7 8
Vertical Angles • Two angles that are opposite angles. • Vertical angels are always congruent! • 13 • 2 4
t 125 ? ? Vertical Angles • Example 1: Find the measures of the missing angles 125 55
B A D l C m AB || CD l || m PARALLEL LINES • Def: line that do not intersect. • Illustration:
Examples of Parallel Lines • Hardwood Floor • Opposite sides of windows, desks, etc. • Parking slots in parking lot • Parallel Parking • Streets: Arizona Avenue and Alma School Rd.
Examples of Parallel Lines • Streets: Belmont & School
Transversal • Def: a line that intersects two lines at different points • Illustration: t
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 ? 108
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
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
1 2 3 4 5 6 7 8 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
Same Side Interior Angles 3 +5 = 180 • 4 +6 = 180 • Two angles that lie between parallel lines on the same sides of the transversal t 1 2 3 4 5 6 7 8
5 6 4 7 8 3 2 t 1 List all pairs of angles that fit the description. • Corresponding • Alternate Interior • Alternate Exterior • Consecutive Interior
Find all angle measures t 180 - 67 113 67 1 3 67 2 113 113 5 67 8 67 6 7 113
Example 5: • find the m 1, if m 3 = 57 • find m 4, if m 5 = 136 • find the m 2, if m 7 = 84
36 x Algebraic Angles = 90 • Name the angle relationship • Are they congruent, complementary or supplementary? • Complementary • Find the value of x x + 36 = 90 -36 -36 x = 54
115 x Example 2 • Name the angle relationship • Vertical • Are they congruent, complementary or supplementary? • Find the value of x x = 115