today in geometry… stats for ch.3.1-3.3 quiz learning goal 2: 3.4 calculate parallel and...
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TODAY IN GEOMETRY…
STATs for Ch.3.1-3.3 Quiz
Learning Goal 2: 3.4 Calculate Parallel and Perpendicular Slopes with a graph and algebraically
Independent Practice
HOW DID YOU “SHAPE” UP??Results for ALL of my Geometry classes:
GRADE NUMBER OF STUDENTS WHO TOOK THE CH.3 QUIZ (17 pts.)
1ST PERIOD 3RD PERIOD 5TH PERIOD 6TH PERIOD TOTAL
A 2 7 7 6 22B 5 9 11 6 31C 6 8 4 7 25D 4 5 1 6 16F 6 0 2 2 10
Avg. 22.54 25.97 26.70 24.91 25.03
KINDS OF SLOPES
UNDEFINED
ZERO
POSITIVE INCREASING
NEGATIVE DECREASING
FORMULA FOR SLOPE:
Used in GraphingUsed when given two points and
REVIEW:
CALCULATING SLOPE WITH A GRAPH
Find the slope of AB
A
B
−𝟓
𝟑
Find two points that are on crosshairs. (exact points)
negative slope = downPositive slope = up
𝑠𝑙𝑜𝑝𝑒=−53
=−53
PRACTICE: Find the slope of the given line.
𝑠𝑙𝑜𝑝𝑒=11
𝟏𝟏
PRACTICE: Find the slope of the given line.
−𝟏𝟐
𝑠𝑙𝑜𝑝𝑒=−12
REVIEW:
CALCULATING SLOPE GIVEN TWO POINTS
Find the slope of AB: A(-2 , 8) B(3 , 2)
𝑥1 , 𝑦1 𝑥2 , 𝑦 2
PREDICT: Do you expect to have an increasing or decreasing slope? NEGATIVE = DECREASING SLOPE
Find the slope of CD: C(5,-2) D(-4,1)
𝑥1 , 𝑦1 𝑥2 , 𝑦 2
PREDICT: Do you expect to have an increasing or decreasing slope? NEGATIVE = DECREASING SLOPE
REVIEW:
SLOPE STEEPNESS
Which line is steeper?
𝑨
𝑩𝑫
𝑪𝑬
𝑭
𝑯
𝑮
−𝟑
−𝟐𝟓
𝟏
𝟒
Greater the absolute value of the slope = steeper
SLOPES OF PARALLEL AND PERPENDICULAR LINES
Under slopes you may also include:
PARALLEL LINES: Two lines that have the same slope.
Ex.
PERPENDICULAR LINES: Two lines that have negative reciprocal slopes. Ex.
Which of the following lines are parallel or perpendicular?
A
B
C
D
E
F
−53
−53
35
Give the PARALLEL and PERPENDICULAR slopes for the following lines.
1. 2. 3.
4. 5. 6.
Parallel Slope:
Perpendicular:
Parallel Slope:
Perpendicular:
Parallel Slope:
Perpendicular:
Parallel Slope:
Perpendicular:
Parallel Slope:
Perpendicular:
Parallel Slope:
Perpendicular:
Line m passes through ( -1 , 3) and (4 , 1). Line t passes through (-2 , -1) and (3 , -3). Are the two lines parallel, perpendicular or neither.*To determine if slopes are you must calculate slope for each line.
have equal slopes, so the two lines are parallel.
Line passes through (3 , 0) and (7 , 6). Graph the line perpendicular to that passes through the point ( 2, 5).*To calculate the perpendicular slope, you must determine the slope first.
𝒍𝒊𝒏𝒆𝒉(𝟐 ,𝟓)
−23
HOMEWORK #4:
Pg. 175: 1-27 odd 28-30
If finished, work on other assignments:
HW #1: Pg. 150: 11-15, 18-23, 24-32, 43-44HW #2: Pg. 157: 4-19, 22-24, 27-31, 33, 35, 36HW #3: Pg. 165: 3-15, 19-21, 23, 26, 27