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10. 12. 15. 18. Year 2 Warm-Up. 1. A. Is D AEB~ D ADC? Why Solve for x. 2. x. B. E. 14. 10. D. C. 2. Are the two triangles similar? why?. Warm-Up Answers:. Yes, by AA (parallel lines imply congruent corresponding angles) x = 14/5 or 2.8
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10 12 15 18 Year 2 Warm-Up 1. A • Is DAEB~DADC? Why • Solve for x 2 x B E 14 10 D C 2. Are the two triangles similar? why?
Warm-Up Answers: • Yes, by AA (parallel lines imply congruent corresponding angles) x = 14/5 or 2.8 2. No, because the corresponding sides are not proportional.
11.3 Indirect Measurement/Applications We can use similar triangles to calculate the height of tall objects that you can’t reach. This is called indirect measurement.
Lets use what we know about similar triangles to find the height of the lamp post. Set up a proportion: Simplify: Cross multiply: Solve: Example #1 Continued x = 15 feet 9 inches
Example #2 About how long is the log that goes across the creek? 9 m 8 m 12 m
Lets use what we know about similar triangles to find the length of the log Set up a proportion: Simplify: Cross multiply: Solve: Example #2 Continued The log is 6 meters
Classwork Option 1: • Make a poster of the assigned problem with all sides labeled • Set up the proportion • Solve • Be prepared to present to the class Problems: pg 582 1,2,3,5,7, 10 pg 614 #7,
Classwork Option 2: Math Lab Group Activity… Break up into groups of no more than 4 and make sure each member of your group has a math lab handout. You will need one meter stick for your group and something to write on and to write with.
If you were asked to find the height of this flagpole… What do you need to know to find the height? And What tools will you need? Summary:
Homework: 11.3 Worksheet