TODAY IN GEOMETRY… STATs for Ch.8 Test Learning Target : 9.1 Given a pre-image, create an image...
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Transcript of TODAY IN GEOMETRY… STATs for Ch.8 Test Learning Target : 9.1 Given a pre-image, create an image...
TODAY IN GEOMETRY…
STATs for Ch.8 Test
Learning Target : 9.1 Given a pre-image, create an image by transformation by translation/slide or reflection
Independent Practice
Ch.8 Retakes
HOW DID YOU “SHAPE” UP??Results for ALL of my Geometry classes:
GRADE NUMBER OF STUDENTS WHO TOOK THE CH.8 TEST (35 pts)
3RD PERIOD 4TH PERIOD 5TH PERIOD TOTAL
A/A- 10 9 11 30B+/B/B- 4 9 9 22C+/C/C- 3 2 4 9
D+/D 5 3 1 9F 5 6 2 13
Average 26.33 26.80 29.15
PRE-IMAGE: Starting figure of a transformation labeled as
IMAGE: Ending figure of a transformation labeled as
TRANSLATION/SLIDE: Moves every point of a figure the same distance in the same direction
𝐴𝐵
𝐶𝐷
𝐴 ′𝐵 ′
𝐶 ′𝐷 ′
𝐴 ′ ′𝐵 ′ ′
𝐶 ′ ′𝐷 ′ ′
Translated/slide 7 units right
Translated/slide 8 units down
x-coordinates change by adding 7
y-coordinates change by subtracting 8
TRANSLATION/SLIDE:
(−5 ,5)→(2 ,5)
PRACTICE: Graph . Translate the Pre-Image and record the image points.
𝐴𝐵
𝐶
𝐴 ′𝐵 ′
𝐶 ′
PRACTICE: Write a rule for the translation of the quadrilateral to quadrilateral .
How did the quadrilateral move?To the right 6 Down 6
Right/Up = ADDLeft/Down = SUBTRACT
Rule:
𝐴𝐵
𝐶 𝐷𝐴 ′𝐵 ′
𝐶 ′ 𝐷 ′
In Class Work #1:
Pg. 576: 3-14, 31
20 minutes then you will turn it in then we are moving on to
reflection.
REFLECTION across the x-axis:
𝐴𝐵
𝐶𝐷
Reflection across the x-axis so the x-axis is the mirror
5
5
𝐴 ′
𝐷′
𝐵′
𝐶 ′
Notice that all x-coordinates of the pre-image and image DOESN’T change but the y-coordinates change signs!RULE:
The distances from the mirror to each point is equal!
REFLECTION across the y-axis:
𝐴𝐵
𝐶𝐷
Reflection across the y-axis so the y-axis is the mirror
33𝐵′
𝐶 ′𝐷′
𝐴′
Notice that all y-coordinates of the pre-image and image DOESN’T change but the x-coordinates change signs!RULE:
The distances from the mirror to each point is equal!
REFLECTION across line :
𝐴𝐵
𝐶𝐷
Reflection across the line
𝐵′𝐶 ′
𝐷′
𝐴′
Notice that the x and y coordinates switch values from pre-image to image.RULE:
REFLECTION across line :
𝐴𝐵
𝐶𝐷
Reflection across the line
𝐷′𝐴 ′
𝐵′
𝐶 ′
Notice that the x and y coordinates switch values from pre-image to image.RULE:
REFLECTION:
(−5 ,5)→(2 ,5)𝑥− 𝑦 (−5 ,5)→(−5 ,−5)−𝑥 𝑦 (−5 ,5)→(5 ,5)
(𝑥 , 𝑦 )→(𝑦 , 𝑥) (−5 ,5)→(5 ,−5)(𝑥 , 𝑦 )→(− 𝑦 ,− 𝑥) (−5 ,5)→(−5 ,5)
PRACTICE: Graph . Reflect the pre-image across the y-axis.
RULE FOR RELECTION ACROSS Y-AXIS:
𝐴𝐵
𝐶
𝐴 ′ 𝐵 ′
𝐶 ′
PRACTICE: Graph . Reflect the pre-image across the line .EACH POINT IN A REFLECTION IS EQUAL DISTANT FROM THE LINE OF REFLECTION
𝐴𝐵
𝐶
𝐴 ′ 𝐵 ′
𝐶 ′
𝑥=1
HOMEWORK #1:
Pg.576: 3-14, 31