Intro to Dilations

​Intro to Dilations

​Key Concepts:

• A DILATION stretches of shrinks a figure.

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• The CENTER OF DILATION never changes position. It is the starting point.

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• ​The SCALE FACTOR tells you how much the dilation stretches or shrinks.

A DILATION is a transformation that produces an image that is the same shape as the pre-image, but is a different size. Dilations create similar figures. 

• Scale factor is greater than 1​

• Image gets BIGGER​

Enlargement

• Scale factor is less than 1​

• ​Image gets SMALLER

​​Reduction

Multiple Choice

First, identify the old and new image. Now, did the triangle get bigger or smaller?

• The triangle got smaller

• The triangle got bigger

Multiple Choice

First, identify the old and new image. Now, did the triangle get bigger or smaller?

• The triangle got smaller

• The triangle got bigger

Multiple Choice

Is this an enlargement or a reduction?

• Enlargement

• Reduction

Multiple Choice

Is this an enlargement or a reduction?

• Enlargement

• Reduction

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

A scale factor of 1/2 reduces a figure.

• True
• False

Multiple Choice

A dilation creates a similar figure, NOT a congruent figure.

• True

• False

Multiple Choice

Dilations always result in CONGRUENT images.

• true

• false

Multiple Choice

A dilation that increases in size will always have a scale factor that is...

• negative

• exactly 1

• greater than 1

• less than 1

Multiple Choice

In this dilation, point A would be considered...

• the center of dilation

• the scale factor

• the center of rotation

• the point of no return