Reflections Lesson

Reflections as Transformations

​Watch this video

On the next slide you will watch a brief video. Take notes as you watch it, paying attention to sign changes for the x and y variables and symmetry with repsct to the line of reflection.

• I can determine the reflection rule when an image is reflected over the x-axis, the y-axis, or the line y = x.

• I can determine the location of an image reflected over any line by determining the distance from the line of reflection.

​

​Learning Targets

Multiple Choice

Select the signs for x and y that correctly map the preimage (blue) onto the image (red).

• (-x, -y)

• (x, -y)

• (-x, y)

• no reflection

Multiple Choice

Select the signs for x and y that correctly map the preimage (blue) onto the image (red).

• (-x, -y)

• (x, -y)

• (-x, y)

• no reflection

Multiple Choice

Select the signs for x and y that correctly map the preimage (blue) onto the image (red).

• (-x, -y)

• (x, -y)

• (-x, y)

• no reflection

Multiple Choice

Select the signs for x and y that correctly map the preimage (blue) onto the image (red).

• (-x, -y)

• (x, -y)

• (-x, y)

• no reflection

Multiple Choice

Select the signs for x and y that correctly map the preimage (blue) onto the image (red).

• (-x, -y)

• (x, -y)

• (-x, y)

• no reflection

Multiple Choice

Select the signs for x and y that correctly map the preimage (blue) onto the image (red).

• (-x, -y)

• (x, -y)

• (-x, y)

• no reflection

Multiple Choice

True or false: When a point is reflected across a line of symmetry, it remains the same distance from the line.

• true

• false

Multiple Choice

True or False: When a figure is reflected over a line of reflection, the new image is congruent to the original.

• True

• False

Multiple Choice

Reflections over the x-axis change the ____-__________.

• y-coordinate

• x-coordinate

Multiple Choice

Find K' if the figure is reflected across the x-axis

• (4, 1)

• (-1, -4)

• (1, -4)

• (1, 4)

Multiple Choice

Reflect over x-axis. Which point would be at (3, -6)

• A

• B

• C

• H

Multiple Choice

What is the line of reflection? 

• Reflection across       y = −2
• Reflection across        y = 2
• Reflection across            x = 2
• Reflection across          x =  −2

Multiple Choice

What is the line of reflection? 

• Reflection across      x-axis
• Reflection across        y-axis
• Reflection across            y = x
• Reflection across          y = −x

Multiple Choice

∆QRS contains the points: Q(4, 2) R(5, 1) S(3,7). If the triangle is reflected across the y-axis, what will S' be?

• S'(3, 7)

• S'(-3, 7)

• S'(-3, -7)

• S'(3, 7)

Multiple Choice

Point C (-5, 4) is reflected over the x-axis. What are the coordinates of C'?

• (5, 4)

• (-5, -4)

• (5, -4)

• (-5, 4)

Multiple Choice

The reflection of J (-1,11) is J' (-1, -11). what is the reflection of D (5, -5) when reflected over the same axis of reflection?

• (-5,5)

• (5,5)

• (5,-5)

• (-5, -5)

Multiple Choice

The point (a, b) is reflected over the y-axis, then the x-axis, then the y-axis again, and then the y-axis again. What are the coordinates of the new point?

• (−a, b)

• (−a, −b)

• (a, −b)

• (a, b)

• I can determine the reflection rule when an image is reflected over the x-axis, the y-axis, or the line y = x.

• I can determine the location of an image reflected over any line by determining the distance from the line of reflection.

​

​Learning Targets

Poll

What is your comfort level with reflections?