TRANSFORMATIONS in the Coordinate Plane

Review: A TRANSFORMATION Figure or point moves to a new position. Size may change, but not shape. A RIGID TRANSFORMATION Figure moves to new position Size and shape remain the same

What are four types of TRANSFORMATIONS? DILATION…(Enlarges or Reduces) TRANSLATION……(Slide) REFLECTION……..(Flip) ROTATION…….…..(Turn)

Things to Remember When working with any TRANSFORMATIONS the original points create the PRE-IMAGE. You can name the points using letters. For example A(4, 5) tells you that “point A is located at position 4, 5 on the graph”. Once the point is moved to its new position it is called a “prime point” and named like this: A’ - read this as “A prime” the figure is now called the IMAGE.

Today we will work with REFLECTIONS Stop and do Reflection Activity Once ACTIVITY is complete, we will come back to the PowerPoint and add to our mini lessons.

which is the (line of symmetry). REFLECTION is a movement of a figure that involves flipping the figure over the given line of reflection. The new prime points will be the same distance from the line of reflection as the original points but on the opposite side of the line of reflection which is the (line of symmetry).

Each will give you the new “prime points”. You have discovered that there are two methods to perform a “REFLECTION”. Each will give you the new “prime points”.

A(-2,3) A’(2, 3) B(-6,3) B’(6, 3) C(-2,7) C’(2, 7) METHOD 1 – over y-axis: From each point, conduct the move requested one point at a time and then draw in your new image. Example: Plot points A(-2, 3), B(-6, 3), and C(-2, 7). Reflect the figure over the y axis. C y C’ STEP 1: Plot original points STEP 2: From each original count the number of units from the y-axis and move the same distance on the opposite side of the y-axis STEP 3: Connect the new points. This is your image and the points are the “prime” points. B B’ A A’ x A(-2,3) A’(2, 3) B(-6,3) B’(6, 3) C(-2,7) C’(2, 7) STEP 4: Now list the location of the new points as your “primes”.

A(-2,3) A’(-2, -3) B(-6,3) B’(-6, -3) C(-2,7) C’(-2, -7) METHOD 1 – over x-axis: From each point, conduct the move requested one point at a time and then draw in your new image. Example: Plot points A(-2, 3), B(-6, 3), and C(-2, 7). Reflect the figure over the x axis. C y STEP 1: Plot original points STEP 2: From each original count the number of units from the x-axis and move the same distance on the opposite side of the x-axis STEP 3: Connect the new points. This is your image and the points are the “prime” points. B A x STEP 4: Now list the location of the new points as your “primes”. A’ B’ A(-2,3) A’(-2, -3) B(-6,3) B’(-6, -3) C(-2,7) C’(-2, -7) C’

y-coordinate if reflecting over the x-axis. METHOD 2: A reflection will only affect the x-coordinate if reflecting over the y-axis and . . . will only affect the y-coordinate if reflecting over the x-axis.

Example : Plot points A(-2, 3), B(-6, 3), and C(-2, 7) and reflect over the y-axis: A (-2, 3) reflected over the y-axis A’ ( 2, 3) B (-6, 3) reflected over the y-axis B’ ( 6, 3) C (-2, 7) reflected over the y-axis C’ ( 2, 7) *NOTE: 1. the x value becomes its own opposite. 2. the y value stays the same. Example 2: Plot points A(-2, 3), B(-6, 3), and C(-2, 7) and reflect over the x-axis: A (-2, 3) reflected over the x-axis A’ (-2, -3) B (-6, 3) reflected over the x-axis B’ (-6, -3) C (-2, 7) reflected over the x-axis C’ (-2, -7) *NOTE: 1. the x value stays the same 2. the y value becomes its own opposite.