Thursday 9/11/14

Warm – Up:1. What are the coordinates of H (-1, -2) after a rotation of 180 degrees clockwise?

2. Point A (8, -4) is reflected over the x-axis. What are the coordinates of A’?

3. Write a rule for the given translation.

4. What is a dilation?

Materials:- HW From Last Night- Loose Leaf Paper for Warm – Up- Pen & Pencil

3 Songs to Unpack and Finish Warm

- Up

Dilations Part 2

4 3 2 1 0In addition to level 3.0 and above and beyond what was taught in class, I may: Make connection

with real-world situations

Make connection with other concepts in math

Make connection with other content areas.

I understand and use informal arguments to prove congruency and similarity using physical models, transparencies or geometry software. informally prove

similarity of triangles

Use scale factors to create and analyze dilations.

I understand congruency and similarity using physical models, transparencies or geometry software. construct

triangles Calculate

dilations with scale factors.

With help from theteacher, I have partial successwith the unit content.

Even with help, I have no success with the unit content.

Learning Goal 1 (8.G.A.3 & 4):The student will understand and use informal arguments to prove congruency and similarity using physical models, transparencies or geometry software.

Dilations make similar figures.

• Similar means:__________________________

• Are the following figures similar? If so, how can you tell?

Same Shape but Different Size

No Yes

What is a scale factor?

This is a Dilation…

3

5

How do you find the scale factor?

Take the second figure’s size and divide it by the first figure’s size.

Is the dilation an enlargement or reduction from the shaded figure to the non-shaded figure.

Enlargement or ReductionScale Factor:

Greater than 1Less than 1

Is the dilation an enlargement or reduction from the shaded figure to the non-shaded figure.

Enlargement or ReductionScale Factor:

Greater than 1Less than 1

Find the scale factor for the dilation from the solid figure to the dashed line figure.

164

4 = 16

1/4

Find the scale factor for the dilation from the solid figure to the dashed line figure.

615

15 = 6

52

Find the scale factor for the dilation from the solid figure to the dashed line figure.