"Measuring the height of the flagpole" similar graphics PPT courseware

Description

"Measuring the height of the flagpole" similar graphics PPT courseware

Activity 1

Read textbook page P141 and answer the following questions:

1. Are the two triangles in Figure 4-20 similar? Why?

2. Use the shadow under the sun to measure the height of the flagpole. What data do you need to measure to calculate the height?

3. If the height of the student is 1.6m, the length of its shadow is 2m, and the length of the shadow of the flagpole is 5m, find the height of the flagpole.

Activity 2

Read textbook page P142 and answer the following questions:

1. How to convert Figure 4-21 into a similar triangle problem by adding auxiliary lines?

2. Use a benchmark to measure the height of the flagpole. What data need to be measured to calculate the height?

3. If the height of the student's eyes from the ground is 1.6m, the benchmark is 2m, the student is 1m away from the benchmark, and the distance between the bottom of the benchmark and the bottom of the flagpole is 5m, find the height of the flagpole.

Practice in class

1. As shown in the picture, two points A and B are located at both ends of a pond. Xiaofang wants to use a rope to measure the distance between points A and B, but the length of the rope is not enough. A classmate helped her come up with an idea. First, pick a point C on the ground that can directly reach points A and B, find the midpoints D and E of AC and BC, and the length of DE is 5m. What is the distance between points A and B?

2. Xiao Ming measured the shadow length of a 2m high bamboo pole under sunlight to be 1.2m. At the same time, he also measured the shadow length of a tree to be 12m. Please calculate the height of the tree.

3. There is a mirror E placed flat on the ground 18 meters away from AB. When people step back to D 2.1 meters away from the mirror, they can see the top of the tree in the mirror. If the human eye is 1.4 meters above the ground, find the height of the tree.

Summary

1. Use the knowledge learned to solve problems by measuring the height of the flagpole.

2. Solve how to connect with the relevant knowledge in the textbook during the operation process.

3. Comprehensively use the judgment and properties of similar triangles to solve practical problems.

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For more information about the PPT courseware "Measure the Height of the Flagpole with Similar Figures", please click on the Measuring the Height of the Flagpole ppt with Similar Figures ppt tag.

"Measuring the Height of the Flagpole" Similar Graphics PPT Courseware 3:

"Measuring the Height of the Flagpole" Similar Figures PPT Courseware 3 Learning Objectives 1. By measuring the height of the flagpole, students can comprehensively use the similar judgment conditions and properties of triangles to solve problems, develop students' awareness of mathematical applications, and deepen students' understanding of similar triangles. 2...

"Measuring the Height of the Flagpole" Similar Graphics PPT Courseware 2:

"Measuring the height of the flagpole" Similar graphics PPT courseware 2 Expand your thinking How can students use the knowledge of similar triangles to measure the height of the flagpole (or street lamp or tree or chimney)? Key points of the method Application method 1: Sunlight can be viewed as parallel approximately Light, when calculating...

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Update Time: 2024-11-03

This template belongs to Mathematics courseware Beijing Normal University eighth grade mathematics volume 2 industry PPT template

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