BUTTERFLIES, PINWHEELS AND WALLPAPER 4 .2 & 4 .3

Similarity Check

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.

What strategies could you use to check the similarity of two figures?

1. How could measurements help you?

2. How could scale factors help you?

3. How could a sequence of transformations help you?

Are the two figures similar?

Measure parts of both figures.

How do we use these numbers to determine if the figures are similar?

Find the scale factor.8 ÷ 24 = 1/33 ÷ 9 = 1/3Since the scale factor is the

same for both sets of sides, the figures are similar.

24 cm

9 cm

8 cm

3 cm

What sequence of transformations changed the red figure into the brown figure?

It could have been a 90˚ clockwise rotation followed by a dilation with a scale factor of 1/3.

Is it possible that it could have been a dilation with a scale factor of 1/3 then a 90˚ clockwise rotation?

24 cm

9 cm

8 cm

3 cm

Labsheet 4.2