"Comparing the Length of Line Segments" Basic Plane Graphics PPT Download

Description

"Comparing the Length of Line Segments" Basic Plane Graphics PPT Download

Part One: Teaching Objectives

1. Understand the property of "the shortest line segment between two points" and the concept of distance between two points.

2. Understand the concept and representation method of the midpoint of a line segment. (difficulty)

3. Be able to compare the length of two line segments with the help of tools such as rulers and compasses (key points and difficulties)

Comparing the length of line segments PPT, part 2: exploration of new knowledge

As shown in the picture, there are four roads from A to B. In addition to them, can we build another shortest road from A to B? If so, please draw the shortest route on the map.

Discover: Among all the lines between two points, the line segment is the shortest

In conclusion

The above findings can be summarized as follows:

The shortest line segment between two points

We call the length of the line segment between two points the distance between the two points.

Example 1 As shown in the figure, the straight line MN represents a railway. There are points A and B on both sides of the railway, representing two factories. It is necessary to build a cargo station on the railway so that the sum of the distances from it to the two factories is the shortest. Where should the cargo station be built?

[Analysis] Select any point P on MN. The distance from it to A and B is the length of the line segments PA and PB. It can be found by combining the shortest line segment between the two points.

Solution: Connect AB and intersect MN at point P, then this cargo station should be built at point P.

In conclusion

(1) The concept of distance between two points describes quantity, not graphics, and refers to the length of the line segment connecting the two points, not the line segment itself.

(2) When solving problems such as selecting a location and finding the shortest distance, it is usually converted into "the shortest line segment between two points".

Comparing the length of line segments PPT, Part 3: Consolidation exercises

1. As shown in the figure, the correct relationship between AC and BD can be obtained from AB=CD ()

A.AC＞BD　B. AC＜BD

C.AC=BD D. Can not be sure

2. It is known that M is the midpoint of line segment AB, ①AB=2AM; ②BM=1/2AB; ③AM=BM; ④AM+BM=AB. Among the above four formulas, the correct one is ()

A. 1 piece B． 2 C． 3 D. 4

3. It is known that line segment AB=6 cm, draw line segment AC=2 cm on straight line AB, then the length of BC is ___________.

Comparing the length of line segments PPT, Part 4 content: Class summary

Compare the length of line segments

The shortest line segment between two points

How to compare line segment sizes

Metrics

Overlay method

Rule and compass drawing

Sum, difference, times and points of line segments

Comparing the length of line segments PPT, Part 5: Classroom quiz

1. It is known that, as shown in the figure, M and N divide the line segment AB into three equal parts, C is the midpoint of NB, and CN=5 cm, then AB=________cm.

2. As shown in the picture, there are three roads ①, ②, and ③ that can be walked from point A to point B ("┍", "┙", and "┕" in the picture indicate right angles), then the _________ road is the shortest, and the other two The relationship between the length of the road is ________.

Keywords: Beijing Normal University edition seventh-grade mathematics PPT courseware free download, comparison of the length of line segments PPT download, basic plane graphics PPT download, .PPT format;

For more information about the PPT courseware "Basic Plane Figures Comparing the Lengths of Line Segments", please click on the Basic Plane Figures PPT Comparing the Lengths of Line Segments PPT tab.

"Comparing the Length of Line Segments" Basic Plane Graphics PPT Teaching Courseware:

"Comparing the Length of Line Segments" Basic Plane Graphics PPT Teaching Courseware Part One: Learning Objectives 1. Understand the properties of the shortest line segment between two points and the concept of distance between two points. 2. Understand the concept and representation method of the midpoint of a line segment. (Difficulty) 3. Be able to use a ruler,...

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"Comparing the Length of Line Segments" Basic Plane Graphics PPT Courseware 3:

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Update Time: 2024-09-11

This template belongs to Mathematics courseware Beijing Normal University Edition Seventh Grade Mathematics Volume 1 industry PPT template

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