Please enter the room quietly place backpacks under the screen. Agenda Thursday, September 19, 2019 Please enter the room quietly place backpacks under the screen. Be seated with all necessary materials, prepared and ready for instructions before the tardy bell rings. Turn in your GREEN Pre-Tests before you sit down. You will need your workbooks. Unit 2, Lesson 2 Concentric Circle Grids Page 15  New seats may be issued this week. Homework: (Due Friday, 9.28.18) Dilations on the coordinate plane. 8.G.A Understand congruence and similarity using physical models, transparencies, or geometry software. Common Core Standards 8.G.3 Describe the effect of dilations, translations, rotations, and reflections on two-dimensional figures using coordinates. 8.G.4 Understand that a two-dimensional figure is similar to another if the second can be obtained from the first by a sequence of rotations, reflections, translations, and dilations; given two similar two-dimensional figures, describe a sequence that exhibits the similarity between them.

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Page 15 Directions: C’ B B’ C A A’ Make a point in the center of the circular grid. This point will serve as the center of dilation. Make a point labeled A as shown. Make a point labeled B as shown. Make a point labeled C as shown. Perform a dilation of Point A using a scale factor of 2. Label new point A’. Perform a dilation of Point B using a scale factor of ½. Label new point B’. Perform a dilation of Point C using a scale factor of 3. Label new point C’. B C’ B’ C How would you describe the distance of each point from the center of dilation? A A’

Page 16 G’ G F’ F H E What scale factor was used in this problem to map Points E, F, G, and H to Points E’, F’, G’, and H’? Explain. H’ E’

Page 17 C’ B’ G F H E D’ A’ Directions (Part 1): Directions (Part 2): 1. Dilate the original polygon ABCD using P as the center of dilation and a scale factor of ½. Label the image of A as E, label the image of B as F, label the image of C as G, and label the image of D as H. 2. Draw segments to form polygon EFGH. D’ A’

Page 19 2.4 Quadrilateral and Concentric Circles Independent Practice: Page 19 2.4 Quadrilateral and Concentric Circles Page 21 Practice Problem # 2 (Directions Continue onto Page 22) Page 23 Practice Problems # 3-4

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Dilate each vertex of triangle ABC using P as the center of dilation and a scale factor of 2. Draw the triangle connecting the three new points. Label Triangle A’B’C’. Dilate each vertex of triangle ABC using P as the center of dilation and a scale factor of ½. Draw the triangle connecting the three new points. Label Triangle A”B”C”. Measure the longest side of each of the three triangles. What do you notice? Measure the angles of each triangle. What do you notice?

Rotation Reflection Translation How would you MAP Triangle ABC to Triangle DEF? (Use either a single transformation or a sequence of transformations) Rigid Transformations: Rotation Reflection Translation

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