"Cut a Geometry" Rich Graphic World PPT

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"Cut a Geometry" Rich Graphic World PPT

Part One: Creating the Situation

Guessing game: It looks green, it turns red when you cut it, and it turns out black when you spit it out. (beat a fruit)

In life, we often need to cut an object into pieces, such as cutting watermelon, sawing wood, etc.

Cutting out a geometric PPT, the second part of the content: exploration of new knowledge

The definition of cross-section: Use a plane to cut a geometric body, and the cut-out surface is called a cross-section.

Think about it: if we use a "knife" to cut a geometric body, what shape might the cut out surface be? Let's take a cube as an example.

cut off

Using a plane to cut a cube, what shape might the surface cut out be?

We can see that the shape of the cross section is a triangle

We can see that the shape of the cross section is an isosceles triangle

We can see that the shape of the cross section is an equilateral triangle

We can see that the shape of the cross section is a square

We can see that the shape of the cross section is a rectangle

We can see that the shape of the cross section is a trapezoid

We can see that the shape of the cross section is a pentagon

We can see that the shape of the cross section is hexagonal

From the previous knowledge, we know that "a line is obtained when a surface intersects a surface." If a plane is used to cut a geometric body, the resulting cross-section is the figure formed by the intersection of the plane and each face of the geometric body. The cube has only six faces, and the cross-section has at most six sides. That is, the hexagon has the most sides.

Cutting out a geometric PPT, the third part: a quick test

1. What are the shapes of the following sections?

2. Indicate the serial number of the cross-sectional shape of the geometry in the figure.

3. According to the diagram, tell the shape of the cross section.

Cutting out a geometric PPT, the fourth part: expansion and improvement

Take a guess:

1. Use a plane to cut a geometric object. If the shape of the cross section is a circle, can you imagine what the original geometric object might be?

2. Use a plane to cut a geometric body. If the shape of the section is a triangle, can you imagine what the original geometric body might be?

read it

In medical diagnosis, there is an instrument and method similar to "section geometry". This is a CT machine, which uses "rays" to examine a certain diseased organ of the patient, just like using a knife to cut off a geometric object.

CT (computed tomography) is a medical imaging diagnostic technology. Its principle is to transmit radiation to the human body, and then use a detector to measure the amount of radiation after transmission. Through computer processing, human body tomographic images are reconstructed and diagnosis is made. The invention of CT is an epoch-making event in the history of medicine. Its designer, inventor and theoretical researcher won the 1979 Nobel Prize in Medicine.

Cutting out a geometry PPT, part 5: Class summary

In this lesson we learned:

1. The definition of cross-section: Use a plane to cut a geometric body, and the cut-out surface is called a cross-section;

2. The cross-section of a cube can be a triangle, quadrilateral, pentagon, or hexagon.

3. Guess the original geometry through the cross-sectional shape.

Cutting a geometry PPT, part 6 content: homework:

1. Use your eyes to find and describe examples of the application of “section” in life;

2. Do the corresponding content in the exercise book and information book.

Keywords: Beijing Normal University Edition seventh-grade mathematics PPT courseware free download, cut a geometry PPT download, rich graphic world PPT download, .PPT format;

For more information about the PPT courseware "Cut a Geometry in a Rich Graphic World", please click on the PPT tab of "Cut a Geometry in a Rich Graphic World".

"Cut a Geometry" Rich Graphic World PPT Courseware 2:

"Cut a Geometry" Rich Graphic World PPT Courseware 2 Definition of Section: Use a plane to cut a geometry, and the cut surface is called a section. Think about it: if we use a knife to cut a geometric body, what shape might the cut out surface be? Take the cube as an example.

"Cut a Geometry" rich graphic world PPT courseware:

"Cut a Geometry" PPT courseware with rich graphic world introduces the principles of CT. In medical diagnosis, there is an instrument and method similar to cutting a geometry. This is a CT machine, which uses rays to examine a patient's diseased organ, just like using a knife to cut off a geometric object. ..

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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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