Understanding Scale Factors in Dilations

In this video, Mr. Stocks teaches how to find the scale factor of a dilation by working through examples of both enlargements and reductions. He explains the process of selecting points from the original and dilated images, determining whether the transformation is an enlargement or reduction, and calculating the scale factor. The video includes practice problems for viewers to try on their own, with solutions provided. Key concepts include understanding the relationship between original and dilated images and verifying calculations with multiple points.

What is the first step in finding the scale factor of a dilation?

• Calculate the area of the shape

• Pick a point from the original image

• Identify the type of transformation

• Draw a new shape

Tags

CCSS.8.G.A.3

If the coordinates of W are (2, 2) and W' are (8, 8), what is the scale factor?

• 5

• 4

• 3

• 2

Tags

CCSS.8.G.A.3

How do you verify the scale factor for an enlargement?

• Check the area of the new shape

• Compare the coordinates of another point

• Measure the perimeter of the new shape

• Count the number of sides

Tags

CCSS.7.G.A.1

What is the scale factor if the coordinates of D are (2, 8) and D' are (1, 4)?

• 1/4

• 1/5

• 1/2

• 1/3

Tags

CCSS.8.G.A.3

How do you confirm the scale factor for a reduction?

• Compare the coordinates of another point

• Check the area of the new shape

• Measure the perimeter of the new shape

• Count the number of sides

Tags

CCSS.8.G.A.3

If Q has coordinates (-3, 2) and Q' has coordinates (-9, 6), what is the scale factor?

• 4

• 3

• 2

• 5

Tags

CCSS.7.G.A.1

What should you do after finding the scale factor for one point?

• Measure the perimeter of the shape

• Calculate the area of the shape

• Draw a new shape

• Check the scale factor with another point

Tags

CCSS.8.G.A.3

If D has coordinates (4, 8) and D' has coordinates (-1, 2), what is the scale factor?

• 1/2

• 1/3

• 1/4

• 1/5

Tags

CCSS.7.G.A.1

What is the scale factor if E has coordinates (8, 4) and E' has coordinates (2, 1)?

• 1/2

• 1/3

• 1/4

• 1/5

Tags

CCSS.7.G.A.1

What should you do if you have any questions about the material?

• Both A and B

• Rewatch the video

• Ask the teacher

• Skip the question