1. Bellwork
1) A landscaper is to install edging around the entire garden. The edging costs $1.39 for each 24in-long strip.
What is the cost of the stripping needed to surround the entire garden?
What is the area of the garden to the nearest tenth of a foot?
2) Tear out Chapter 9 from the core book: pgs 365 – 413, EXCEPT pg on dilations

2. 9-1 Reflections
Rigor – Students will correctly reflect images over a given line of reflection and understand the definition of a reflection
Relevance – Reflections describe rigid motion

3. Exlploration activity into reflections
Turn in your core book to pg 369 example 1 and follow the instructions in the bullets to reflect the triangle and quadrilateral. Use scratch paper instead of tracing paper.
Draw a segment connecting corresponding vertices of the pre-image and image.
Measure the distance along that segment from each vertex to the line of reflection in centimeters. What do you notice?

4. Reflection defined
A reflection is a rigid transformation so that the line of reflection is a perpendicular bisector for the segments connecting each pre-image point to its corresponding image.

5. Reflection Methods: On graph paper Not on graph paper
Draw line of reflection
Count horizontal/vertical spaces from the vertex to the line of reflection
Count the same number of spaces on the other side of the line of reflection and plot the image
Not on graph paper
Use a ruler to draw segments from each vertex and perpendicular to the line of reflection
Measure the distance from the vertex to the line of reflection
Measure the same distance on the other side and plot the image.

6. Function Notation for Reflections
𝑅 𝑙𝑖𝑛𝑒 𝑜𝑓 𝑟𝑒𝑓𝑙𝑒𝑐𝑡𝑖𝑜𝑛 (𝑝𝑟𝑒−𝑖𝑚𝑎𝑔𝑒)
“Reflect triangle ABC across the line y = 4” would be written as 𝑅 𝑦=4 (∆𝐴𝐵𝐶)
Highlight the reflection rules for the coordinate plane on core book pg371

7. Examples to put into notes
Core book pg 370 – 371 examples 2 and 3

8. Standard: 9-1 Classwork
Part A: Core book pg 372 – #1, 4, 6, 8 – 11, 19
Part B: Reflections worksheet (resource page 1.2.1)
For problem #52, after graphing the equations, reflect y = x2 + 3 across y = x.

9. Honors: 9-1 Classwork
Part A: Core book pg 372 – #1, 4, 6, 8 – 11, 19, 20
Part B: Reflections worksheet (resource page 1.2.1)
For problem #52, after graphing the equations, reflect y = x2 + 3 across y = x.