1. Lesson 9-7 Pages 471-475 Similar Triangles and Indirect Measurement Lesson Check 9-6 Lesson Check 9-5

2. What you will learn! 1.How to identify corresponding parts and find missing measures of similar triangles. 2.Solve problems involving indirect measurement using similar triangles.

3. Similar triangles Indirect measurement

4. What you really need to know! Similar triangles are triangles that have the same shape but not necessarily the same size. If two triangles are similar, then the corresponding angles have the same measure, and the corresponding sides are proportional.

5. What you really need to know! The properties of similar triangles can be used to find measurements which are difficult to measure directly. This is called indirect measurement.

7. Example 1: If ∆RUN ~ ∆CAB, what is the value of x?

8. Example 2: A surveyor wants to find the distance RS across the lake. He constructs ∆PQT similar to ∆PRS and measures the distances as shown. What is the distance across the lake?

10. Example 3: Suppose the John Hancock Center in Chicago, Illinois, casts a 257.5 foot shadow at the same time a nearby tourist casts a 1.5 foot shadow. If the tourist is 6 feet tall, how tall is the John Hancock Center?

11. x 257.5 ft 6 ft 1.5 ft

13. Page 473 Guided Practice #’s 3-6

15. Pages 471-473 with someone at home and study examples! Read:

16. Homework: Pages 474-475 #’s 7-18 #’s 21-22, 26, 27, 29-35 Lesson Check 9-7

21. Page 747 Lesson 9-7

22. Lesson Check 9-7

23. Study Guide and Review Pages 483-485 #’s 1-24, 34-35 (Odd answers in back of book)

33. Prepare for Test! Pages 487 #’s 1-14, 16, 20 Lesson Check Ch-9Lesson Check 9-7

37. Prepare for Test! Pages 488-489 #’s 1-23