lesson 2: reflecting shapes. when doing reflections… you use a line of reflection no matter where...

Lesson 2: Reflecting Shapes

When Doing Reflections…• You use a line of reflection• No matter where the shape is in relation to the line of reflection, the image is always the same distance from the line as the original shape• Reflections can be horizontal, veritcal and diagonal• Important: You must label each of the vertices of the image and name the ordered pair for each

Example 1

Example 2

Positional Change of the Vertices

• The shape and image have opposite orientation after reflection

• The 2-D shape and its reflected image are congruent

• There is an equal distance from the mirror line to both the 2-D and reflected image

Reflecting the Shapes Horizontally

• When reflecting a 2-D shape across a horizontal line of reflection, the x-coordinates do not change, but the y-coordinates does change

Reflecting the Shapes Vertically

• When reflecting across a vertical line, x-coordinates change and y-coordinates do not change

Example 3

1. Reflect Parallelogram ABCD using each reflection line and draw the image each time

2. Label the vertices of each image3. Describe the distance of the image from the line of reflection4. Describe the orientation

Reflecting the Lines Diagonally

• When reflecting on a diagonal line of reflection, both x and y-coordinates change!!!

• Read together on page 151

• DO THE QUESTION!!!