1. State whether each figure has rotational symmetry. Write yes or no
State whether each figure has rotational symmetry. Write yes or no. If so, locate the center of symmetry, and state the order and magnitude of symmetry.
Problem of the Day

2. Section 9-6 Dilations

3. Then
Now
Objectives
You identified dilations and verified them as similarity transformations.
Draw dilations.
Draw dilations in the coordinate plane.

4. Common Core State Standards
Content Standards
G.CO.2 – Represent transformations in the plane; describe transformations as functions. Compare transformations that preserve distance and angle to those that do not.
G.SRT.1 – Understand similarity in terms of similarity transformations. Verify experimentally the properties of dilations.
Mathematical Practices
1) Make sense of problems and persevere in solving them.
5) Use appropriate tools strategically.
Common Core State Standards

5. A dilation is a transformation that enlarges or reduces the original figure proportionally. Since a dilation produces a similar figure, a dilation is a type of similarity transformation. Dilations are performed with respect to a fixed point called the center of dilation. The scale factor of a dilation describes the extent of the dilation.
Vocabulary

8. Determine whether the dilation from Figure Q to Q’ is an enlargement or a reduction. Then find the scale factor of the dilation and x.
Example 2

9. Determine whether the dilation from Figure K to K’ is an enlargement or a reduction. Then find the scale factor of the dilation and x.
Example 2

11. Find the image of each polygon with the given vertices after a dilation centered at the origin with the given scale factor: Q(0, 6), R(-6, -3), S(6, -3); k = 1/3
Example 3

12. Find the image of each polygon with the given vertices after a dilation centered at the origin with the given scale factor: A(2, 1), B(0, 3), C(-1, 2), D(0, 1); k = 2
Example 3

13. Find the image of each polygon with the given vertices after a dilation centered at the origin with the given scale factor: S(0, 0), T(-4, 0), V(-8, -8); k = 1.25
Example 3

14. Find the image of each polygon with the given vertices after a dilation centered at the origin with the given scale factor: D(4, 4), F(0, 0), G(8, 0); k = 0.75
Example 3

15. p.678 #15 – 18 all, 21, 23, 25, 46 – 48 all
Homework

16. Problem of the Day If PQ = 6 and P’Q’ = 12, then the dilation is a/an:
Enlargement
Reduction
Congruence transformation
None of these
Problem of the Day