1. 8.1/8.2 Reflections Warm-up (IN)
Learning Objective: To draw lines of reflection, and reflected images, to use reflections to solve real world problems, and to discover how coordinates change after a reflection
Warm-up (IN)
15 Minutes - The first part of the warm-up will be a review of the last lesson, and the 2nd is an algebra review to prepare the students for the algebra that will be done in the notes and homework with isosceles triangles.
20 minutes – Check answers to even problems from HW, then to over any questions.

2. Notes Reflection – Preserves congruence Changes orientation
Learning Objective: To draw lines of reflection, and reflected images, to use reflections to solve real world problems, and to discover how coordinates change after a reflection
Notes
Reflection –
Preserves congruence
Changes orientation
The line of reflection is the perpendicular bisector of every segment that connects a point and its image
41 minutes for notes
Essential Questions:
What is the isosceles triangle theorem and it’s converse?

3. CKC p. 394 #1-5 Answer in your notes!
Learning Objective: To draw lines of reflection, and reflected images, to use reflections to solve real world problems, and to discover how coordinates change after a reflection
Ex 1 – copy the diagram and draw the image of ΔLMN after reflection over line j.
L is on the line of reflection, so it doesn’t change L M N N’ L‘
Essential Questions:
How can you use the Isosceles triangle theorem to write a paragraph proof? M’
CKC p. 394 #1-5 Answer in your notes!

4. Learning Objective: To draw lines of reflection, and reflected images, to use reflections to solve real world problems, and to discover how coordinates change after a reflection
Ex 2 – Reflect quadrilateral HATS over the x-axis. Give the coordinates of the image.
(1,1) H A T S H H’
(1,-1) A
(2,4) A’
(2,-4) T
(5,4) T’
(5,-4) S
(6,1) S’
(6,-1) H’ S’ A’ T’

5. Reflecting over the Coordinate axes –
Learning Objective: To draw lines of reflection, and reflected images, to use reflections to solve real world problems, and to discover how coordinates change after a reflection
Reflecting over the Coordinate axes –
When a point (a,b) is reflected over a coordinate axis, one coordinate changes to its opposite and the other coordinate does not change.
Reflection over x-axis
Reflection over y-axis
(a,b)
(-a,b)
(a,b)
(a,-b)

6. Reflecting over the line y=x –
Learning Objective: To draw lines of reflection, and reflected images, to use reflections to solve real world problems, and to discover how coordinates change after a reflection
Reflecting over the line y=x –
The coordinates are reversed
Y=x
(b,a)
(a,b)

7. Learning Objective: To draw lines of reflection, and reflected images, to use reflections to solve real world problems, and to discover how coordinates change after a reflection
Ex 3 – Reflect ΔDAY over the line y=x. Give the coordinates of the image.
Y=x
(-3,0) D A Y D D’
(0,-3) A
(2,1) A’
(1,2) Y
(-4,-4) Y’
(-4,-4) A’ D’ Y’

9. HW – you’ll find out next class!
Out – Describe what happens to coordinates when they are reflected over the x-axis, the y-axis and y=x.
Summary – I have a question about…or, I get…
HW – you’ll find out next class!
5 minutes for Summary and closing questions.
I will have the students do the Out as a ticket out.