Dilations and Similarity Lesson

Dilations & Similarity

​Dilation:
A transformation that changes the size of a figure but not its shape.

Multiple Choice

A dilation is which of the following:

• only an enlargement

• only a reduction

• either an enlargement or a reduction

• neither an enlargement nor a reduction

Multiple Choice

A dilation always produces a congruent figure.

• True

• False

Multiple Choice

A dilation always produces a similar figure. Similar figures have the same ______ but different ______.

• measure; shapes

• sizes; shapes

• value; measures

• shape; sizes

Multiple Choice

Did the image enlarge, reduce or none of the above?

• Enlarge

• Reduce

• None of the above

Multiple Choice

Does the image show a Dilation? If yes, did the image enlarge, reduce or none of the above?

• Yes, enlarge

• Yes, reduce

• No

Multiple Choice

Under a dilation, which scale factor will result in a congruent image?

• -2

• 0

• 1

• ¹/₂

Multiple Choice

An image is dilated at a scale factor of 1.5. This means the dilation is an enlargement and the dilated image will be bigger.

• True

• False

Multiple Choice

State the coordinate of the image of the given point B (4,9) under a dilation with center at the origin with the given scale factor of 2.

• B' (2 , 4.5)

• B' (-8 ,-18)

• B' (8 ,18)

• B' (9 ,4)

Multiple Choice

Dilate the figure by a scale factor of 3 with the origin as the center of dilation. What are the coordinates of the image?

A(3,3) B(6,6) C(9,3)

• A'(9,9) B'(18,18) C'(27,9)

• A'(6,6) B'(9,9) C'(12,6)

• A'(0,0) B'(3,3) C'(6,0)

• A'(1,1) B'(2,2) C'(3,1)

Drag and Drop

In this figure, triangle TRS is the ​

Placeholder

, triangle T'R'S' is the ​

Placeholder

and a(n) ​

Placeholder

occurred.

Drag these tiles and drop them in the correct blank above

pre-image

image

enlargement

reduction

spin

flip

Multiple Choice

If the scale factor is less than one, the new figure will be

• an enlargement
• a reduction
• a scale factor
• bigger

Multiple Choice

If the scale factor is greater than one, the new figure will be

• a reduction
• an enlargement
• a scale
• not proportional

Multiple Choice

What is the scale factor from ΔDEF to ΔABC?

• 1/2
• 7/3
• 2
• 10/3

Multiple Choice

sf = 0.8

• Reduction
• Enlargement

Multiple Choice

sf = 6/5

• Reduction
• Enlargement

Multiple Choice

All angles in similar figures are congruent.  

• True
• False

Multiple Choice

The two rectangles are scale drawings. What is the measurement of x?

• 21
• 1.25
• 20
• 4

Multiple Choice

Two objects that are the same shape but not the same size are _______.

• Congruent
• Vertical
• Similar
• Complementary 

Poll

How did you feel about this lesson?

• Still no clue

• I'm getting about half

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• I understand completely