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Session 4 - Similarity, Right Triangles, and Trigonometry
Step 4
Connect: Closing the Lesson (20 minutes):
Activity: Height of a Streetlamp
Activity: Height of a Streetlamp
Focus: MP3: Construct viable arguments and critique the reasoning of others and MP4: Model with mathematics
Directions for Giving the Task:
- To solve this problem you need to set up the ratio of the sides according to their similarity and solve for the unknown. Since the flagpole's height and its shadow are similar to the triangle of the person and their shadow, we set the proportion of the flagpole: shadow and person: shadow
- The idea is to help students understand why they need different math skills to solve this problem.
- Use your knowledge of similar triangles and proportions to find the height of the street lamp. Directions can be found on the worksheet as well.
- Set up equivalent fractions h18=56.
- If students use equivalent fractions they will see that h=15.
Why are students doing this/what are they getting out of it?
Students will demonstrate if their skill has been generalized by attempting a similar problem but with different triangles of similarity.
Please Note
If this activity seems to be taking a long time, this would be a good breaking point.
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