1. Warm-Up
What is the scale factor of ABC to DEF?

2. Similarity – Day 7
Dilations

3. Dilation Practice

4. Dilation
Nonrigid transformation in which the image and preimage are similar.
Center C and scale factor k:
If P is not the center point, then P’ lies on CP.
If P is the center point, then P=P’

5. Dilation
Nonrigid transformation in which the image and preimage are similar.
Center C and scale factor k

6. Dilation
Reduction if 0 < k < 1.
Enlargement if k > 1.

7. Example 1:
Identify the dilation and its scale factor.

8. Example 2:
Identify the dilation and its scale factor.

9. Example 3:
X(1, 4)
Y(1, 1)
Z(5, 1)

10. Example 4:
A circle in a photocopier enlargement has a 6 in diameter. If the enlargement is 125% of the original, what is the diameter of the image of the circle?

11. Guided Practice

12. Drawing a dilation Draw a triangle and label it PQR.
Make a point outside of the triangle and name it C.
Use the ruler to draw rays from C through the vertices of the triangle.
Use the compass to locate P’ on CP so that CP’ = 2(CP).
Repeat for Q’and R’.
Connect the points P’, Q’, and R’. P’ Q P R C

13. Homework