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2.07 Warm-up

Dilating a figure by a scale factor of 2.

  1. Construct a ray from the center to each vertex of the figure.
  2. Use the compass to construct a circle with radius AC centered at C. Then, mark the point of intersection of the circle and ray AC.
  3. Use the compass to construct a circle with radius AB centered at B. Then, mark the point of intersection of the circle and ray AB.
  4. Use the segment tool to connect the endpoints of your dilated segment.

Follow the steps above to dilate the segment BC by a scale factor of 2 from center A.

Is the dilated segment still a segment?

How can we be sure that the dilation maps the points between B and C to the points between the segment endpoints in the dilated image? Perhaps the dilation maps the endpoints the way we expect, but all other points form an arc or some other curve that connects the endpoint. Can you think of a way we can verify that all of the points on segment BC map to the dilated image? Hint: Think about what we learned yesterday about the coordinates of the pre-image and the image.

From the properties of dilations, what do we know to be true about the pre-image segment and the image segment?

Select all that apply
  • A
  • B
  • C
Check my answer (3)