# What is a Dilation? - PowerPoint PPT Presentation

1 / 12

What is a Dilation?. Dilation is a transformation that produces a figure similar to the original by proportionally shrinking or stretching the figure. Dilated PowerPoint Slide. Transformation Geometry Dilations. Proportionally. Let’s take a look….

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

What is a Dilation?

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

### What is a Dilation?

• Dilation is a transformation that produces a figure similar to the original by proportionally shrinking or stretching the figure.

Dilated PowerPoint Slide

## Transformation GeometryDilations

### Proportionally

Let’s take a look…

And, of course, increasing the circle increases the diameter.

• When a figure is dilated, it must be proportionally larger or smaller than the original.

So, we always have a circle with a certain diameter. We are just changing the size or scale.

Decreasing the size of the circle decreases the diameter.

We have a circle with a certain diameter.

• Same shape, Different scale.

A

HINT: SAME SHAPE, DIFFERENT SIZE

C

D

B

### Scale Factor and Center of Dilation

When we describe dilations we use the terms scale factor and center of dilation.

• Scale factor

• Center of Dilation

Here we have Igor. He is 3 feet tall and the greatest width across his body is 2 feet.

He wishes he were 6 feet tall with a width of 4 feet.

His center of dilation would be where the length and greatest width of his body intersect.

He wishes he were larger by a scale factor of 2.

### Scale Factor

• If the scale factor is larger than 1, the figure is enlarged.

• If the scale factor is between 1 and 0, the figure is reduced in size.

Scale factor > 1

0 < Scale Factor < 1

### Using the scale factor to dilate

• A triangle has vertices A(4, -4), B(8,2) and C(8, -4). The image of triangle ABC after a dilation with a scale factor of ½ is triangle DEF. Find the coordinates and sketch the graph.

### Are the following enlarged or reduced??

C

A

Scale factor of 1.5

D

Scale factor of 3

B

Scale factor of 0.75

Scale factor of 1/5

### Book Practice pg 412 #5, 10, 12

• Use graph paper if applicable.

B’

C’

A’

B

A

C

### The Object and the Image

• The original figure is called the object and the new figure is called the image.

• The object is labeled with letters.

• The image may be labeled with the same letters followed by the prime symbol.

Image

Object

### Remember

• Dilations areenlargementsorreductions.

• What are some things that you would not

mind dilating to make larger or smaller?

Practice Dilation Quiz