Dilation and Scale Factors in Geometry

The video tutorial covers geometric transformations, focusing on dilation. It explains how dilation uses a scale factor to enlarge or reduce geometric figures. Several examples illustrate the concept, including dilating a triangle and calculating scale factors for enlargements and reductions. The video emphasizes understanding the relationship between scale factors and image size changes.

What is a transformation in geometry?

• A process that changes the color of a figure

• An operation that maps a figure onto a new figure

• A technique to measure angles in a figure

• A method to calculate the area of a figure

What happens to a figure when it is dilated with a scale factor greater than 1?

• The figure becomes smaller

• The figure remains the same size

• The figure becomes larger

• The figure changes shape

In the example with a scale factor of 1/2, what happens to the size of the triangle?

• The triangle becomes larger

• The triangle remains the same size

• The triangle changes shape

• The triangle becomes smaller

How do you calculate the new coordinates of a point after dilation with a scale factor of 1/2?

• Subtract 1/2 from each coordinate

• Multiply each coordinate by 1/2

• Divide each coordinate by 1/2

• Add 1/2 to each coordinate

What is the result of dilating a quadrilateral with a scale factor of 3?

• The quadrilateral becomes smaller

• The quadrilateral remains the same size

• The quadrilateral changes shape

• The quadrilateral becomes larger

When a scale factor is greater than 1, what happens to the image compared to the preimage?

• The image is smaller than the preimage

• The image is larger than the preimage

• The image is the same size as the preimage

• The image changes shape

How do you determine the scale factor of a dilation when given the original and dilated sizes?

• Divide the original size by the dilated size

• Multiply the original size by the dilated size

• Divide the dilated size by the original size

• Subtract the original size from the dilated size

In the microscope example, what is the scale factor if the original diameter is 0.25 mm and the dilated diameter is 11.25 mm?

• 1

• 11.25

• 0.25

• 45

What is the scale factor when reducing a scanned photograph from 1080 pixels to 720 pixels?

• 3

• 2/3

• 3/2

• 1/2

What remains the same in a figure after dilation?

• The size

• The shape

• The color

• The position