This document contains notes from four geometry lessons on similar and congruent figures, scale factors, ratios, and proportions. It includes vocabulary definitions, examples worked out in class, and homework assignments for students to practice the concepts taught each day. The lessons focus on justifying congruency and symmetry of figures and solving problems using scale factors, ratios, and proportions.

1. 3c: Justify congruency and symmetry of two figures (DOK 2)4d: Solve problems involving scale factors using ratios and proportions (DOK 2) By: Deia Sanders

2. Study these pictures Similar or Congruent?

3. Vocabulary Similar: two polygons are similar if the corresponding sides are in the same proportion; if the polygons are similar, the corresponding angles will be equal.

4. Let’s look at pages 138 and 139

5. Homework Handout #1 Pages 155-157

6. Day 2 3c: Justify congruency and symmetry of two figures (DOK 2)4d: Solve problems involving scale factors using ratios and proportions (DOK 2)

7. Let’s Review from yesterday Please exchange papers to check homework

8. Find Missing Lengths Using Proportions Turn to pages 140-141

9. Examples

10. Homework Complete Handout #2 pages 159-160

11. Day 3 3c: Justify congruency and symmetry of two figures (DOK 2)4d: Solve problems involving scale factors using ratios and proportions (DOK 2)

12. Let’s Review from yesterday Please exchange papers to check homework for a grade

13. Vocabulary Line of symmetry: a line is a line of symmetry for a figure if the reflection of every point on that figure with respect to the line is also a point of the figure (Where you can fold and object and it’s the exact same on both sides)

14. Turn to page 142

15. Examples

16. Homework Handout #3 Page 162

17. Closure Where could we fold you to find your line of symmetry?

18. Day 4 3c: Justify congruency and symmetry of two figures (DOK 2)4d: Solve problems involving scale factors using ratios and proportions (DOK 2)

19. Congruent: if two polygons are congruent, then their corresponding or matching sides and angles are also congruent. Congruent figures are also similar, so the corresponding sides can also be found using ratios. Vocabulary

20. Congruent = Same

21. Turn to the bottom of page 142 and page 143

22. Secret trick The sides and angles of polygons are listed the same order, or order of congruence. You can line up the letters from each figure on top of each other and it will match up the congruent sides and angles.

23. Examples

24. Homework Handout #4 Page 164