Scale Factor
Sequencing Dilations
Finding coordinates before / after a dilation
Properties of dilations
100
What is the scale factor that would map line segment AB ,9 cm, to line segment A'B' ,18 cm?
r=2
100
Describe the sequence of dilations:
Dilate with a scale factor of 3 and reflect across the y-axis
100
Point A (20, 10) was dilated by a scale factor of 1/2. What are the coordinates of A'?
A' (10, 5)
100

Is a dilation of 5/3 reduction or enlargement a figure?

Enlargement

200
A(3, 6) A' (9, 18) What is the scale factor?
r=3
200
Describe the sequence of dilations
Dilate with a scale factor of ½ and rotate 90 clockwise
200
Point A (2,3), Point B (1, -4), and Point C (1, 1) were dilated by a scale factor of 2. What are the coordinates of A', B', C'?
A'(4,6) B'(2, -8) C'(2, 2)
200
Angle B is 72 degrees. After a dilation of 1/2, what is the measure of angle B'?
72 degrees.
300
A(12, 6) A' (2, 1) What is the scale factor?
r=1/6
300

Determine the coordinates for A(3, 3) after a sequence of dilation with a scale factor of 2 and a translation of 2 to the right.

(8, 6)

300

determine the image's coordinates if r=12 A(4 , 5) B (1, 2) C( 1, 3), D (9, 6).

A'(48, 60) B'(12, 24) C'(12, 36) D'(108, 72)

300

What stays the same in dilations?

Angle measure and shape

400
How do you find scale factor?
Divide the image length by the original length
400
Determine the coordinates of B (10, -4) after a dilation of 1/2 and a reflection across the y-axis.
B' (5, 4)
400
How do you find coordinates after a dilation?
Multiply the original coordinates by the scale factor.
400

What are the two things you need to list for a dilation?

A center and scale factor

500
If a figure is getting larger the scale factor is ________. If a figure is getting smaller the scale factor is ________.
greater than 1, r>1 Less than 1, but greater than 0, 0<r<1
500
Describe the sequence of transformations:
Dilate with a scale factor of 1/3 and translate 5 units right
500
A' (4, 8) B' (2, 5) C' (3,1) Determine the original coordinates if the scale factor is r = 1/2
A(8, 16) B(4, 10) C (6,2)
500

When is a time in real-life that dilations are used?

Ads, building models (blue prints), etc...

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