1. Bellwork Solve Solve Solve for x Solve for x Two similar triangles have a scale factor of 2. The sum of the angles in the first triangle is 180 o. What is the sum of the angles in the second triangle Two similar triangles have a scale factor of 2. The sum of the angles in the first triangle is 180 o. What is the sum of the angles in the second triangle Find the equation of the line that goes through (1,2) and (4, 5) Find the equation of the line that goes through (1,2) and (4, 5) 15 x 12 8 AB C DE F No Clickers

2. Bellwork Solution Solve Solve

3. Bellwork Solution Solve for x Solve for x 15 x 12 8 AB C DE F

4. Bellwork Solution Two similar triangles have a scale factor of 2. The sum of the angles in the first triangle is 180 o. What is the sum of the angles in the second triangle Two similar triangles have a scale factor of 2. The sum of the angles in the first triangle is 180 o. What is the sum of the angles in the second triangle

5. Bellwork Solution Find the equation of the line that goes through (1,2) and (4, 5) Find the equation of the line that goes through (1,2) and (4, 5)

6. Prove Triangles Similar by AA Section 6.4

7. The Concept In chapter 4 we saw the different ways to prove triangle congruence. In chapter 4 we saw the different ways to prove triangle congruence. In chapter 6 we are going to look at the different ways that we can prove triangle similarity In chapter 6 we are going to look at the different ways that we can prove triangle similarity

8. Activity ☻

9. Postulate Postulate 22: Angle-Angle Similarity Postulate If two angles of one triangle are congruent to two angles of another triangle, then the two triangles are similar.

10. Postulates in action… Let’s look at Example 2

11. Example Are the two triangles similar? If so, write a congruency statement Note: Lines m & n are parallel DE C AB

12. Example A school building casts a shadow that is 26 feet long. At the same time, a student standing nearby, who is 71 inches tall, casts a shadow that is 48 inches long. How tall is the building to the nearest foot. 48” ☻ 71” 26’ x

13. Homework 6.4 6.4 1, 2-12 even, 15-25, 31-37, 42-48 1, 2-12 even, 15-25, 31-37, 42-48

14. Most Important Points AA Similarity Postulate AA Similarity Postulate