Unit 7 Review (da #3)

Unit 7: Transformation Review

Reflections, Translations, Rotations, Dilation, Multiple Transformations

Rules Cheat Sheet:

As you work through the slides...

Create a cheat sheet that includes the rules for reflections, translations, rotations and dilations. Determine on your sheet which are congruent and which are similar.

Reflection

Represents the flipping of an image

When an object is reflected, the pre-image and image are always congruent (SAME SIZE AND SAME SHAPE)

Rules

• Over the x-axis  (x, -y) = This means keep the sign of x and change the sign of y 

• Over the y-axis (-x, y) = This means change the sign of x and keep the sign of y 

Multiple Choice

Which answer shows a reflection across the x-axis?

• d

• c

• b

• a

Multiple Choice

What would be the coordinates of point K if it was reflected over the Y-axis?

• (-5, 2)

• (5, 2)

• (5, -2)

Translation Notations

Slide Horizontally (left/right) and/or Vertically (up/down)

Multiple Choice

Determine the correct translation rule?

• $$\left(x,\ y\right)\rightarrow\left(x-7,\ \ y\right)$$

• $$\left(x,\ y\right)\rightarrow\left(x+7,\ \ y\right)$$

• $$\left(x,\ y\right)\rightarrow\left(x,\ y-7\right)$$

• $$\left(x,\ y\right)\rightarrow\left(x,\ y+7\right)$$

Multiple Choice

Determine the translation rule?

• $$\left(x,\ y\right)\rightarrow\left(x+10,\ y+10\right)$$

• $$\left(x,\ y\right)\rightarrow\left(x+10,\ y-10\right)$$

• $$\left(x,\ y\right)\rightarrow\left(x-10,\ y+10\right)$$

• $$\left(x,\ y\right)\rightarrow\left(x-10,\ y-10\right)$$

Rotations

Multiple Choice

What type of rotation does this represent (from red to blue)?

• 270⁰ clockwise

• 180⁰

• 90⁰ clockwise

Multiple Choice

If you were to rotate ABCD 180° about the origin, what would the coordinate of A' be?

• (-5, 5)

• (-3, -5)

• (-5, 3)

• (-3, 3)

Multiple Choice

Rotation Rules (clockwise):

90^o rotation: (x, y)→(y, -x)

What are the coordinates for A' after a 90^⁰ rotation clockwise?

• (1, 3)

• (3, 1)

• (3, -1)

• (1, -3)

Multiple Choice

Triangle ABC is dilated by a scale factor of $$8$$ to form Triangle A’B’C’ with the origin as a center of dilation. Which rule represents this dilation? 

• $$(8x,8y)\ \rightarrow\ (x,y)\$$  

• $$(x,y)\ \ \rightarrow\ \ (x+8,\ y-8​)$$  

• $$(x,y)\ \rightarrow\ (8x,\ 8y)$$  

• $$(x,y)\ \ \rightarrow\ \ (\frac{x}{8},\ \frac{y}{8})$$  

Multiple Choice

What is the scale factor?

• 1

• 2

• 3

• 4

Multiple Choice

State the coordinate of the image of the given point B (4,9) under a dilation with center at the origin with the given scale factor of 2.

• B' (2 , 4.5)

• B' (-8 ,-18)

• B' (8 ,18)

• B' (9 ,4)

Multiple Choice

Dilate Point B by a scale factor of 3:

• (12,0)

• (12,12)

• (4,3)

• (0,12)