"Three Views" Projection and View PPT Download

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"Three Views" Projection and View PPT Download

Part One: Learning Objectives

1. Be able to understand the concept of view from the perspective of projection and clarify the relationship between view and projection.

2. Be able to identify three-dimensional views of objects and draw three-dimensional views of simple geometric objects. (Key points and difficulties)

Import new lesson

Situation introduction

"It looks like a ridge on the side and a peak on the side, with different heights near and far. I don't know the true face of Mount Lu, just because I am in this mountain." Can you explain the reason?

Three-view PPT, part 2: teaching new lessons

The concept and relationship of three views

Observe and think

The picture below shows the design drawings of an aircraft. Can you point out the directions from which the objects are depicted in these design drawings?

When we observe an object from a certain direction, the shape we see is called a view of the object. The view can also be regarded as the orthographic projection of an object under light in a certain direction. For the same object, if observed from different directions, the views obtained may be different. In this chapter we only discuss three views.

1. Three projection surfaces

We use three mutually perpendicular planes (for example: three walls at the corner) as the projection plane. The one facing us is called the front, the one below the front is called the horizontal plane, and the one on the right is called the side.

2. Three views

Expand the three projection planes in a plane to obtain a three-dimensional view of the object.

Three-view is the collective name for the front view, top view, and left view. It is a common view that represents the shape of an object from three directions.

Three-view drawing method

Analysis of classic examples

Example 1 Draw three views of the basic geometry in the figure:

induction:

The specific drawing method of three views is:

1. Determine the position of the main view and draw the main view;

2. Draw a top view directly below the main view, paying attention to aligning it with the length of the main view;

3. Draw the left view directly to the right of the main view, making sure that the height is flush with the main view and the width is equal to the top view;

4. In order to represent the symmetry axis of a cylinder, cone, etc., it is stipulated that a dotted line should be drawn in the view to represent the symmetry axis.

Note: Invisible contours are drawn with dotted lines.

Example 2 Draw three views of the bracket as shown in the figure, in which the height and width of the two steps of the bracket are equal.

Three-view PPT, the third part: practice in class

1. In the geometry in the figure below, the front view, left view, and top view are all the same ( )

2. If the three views of a geometry have the same shape and equal size, then the geometry cannot be ()

A. ball b. Triangular pyramid C. Cube D. cylinder

3. The front and top views of the geometry formed by rotating the rectangular cardboard 180° around one of its sides cannot be ( )

A. Rectangle, rectangle B. Semicircle, rectangle

C． Circle, rectangle D. Rectangle, semicircle

4. The top view of the geometry placed as shown in the figure is ( )

Three-view PPT, Part 4: Class Summary

Three View

The concept and relationship of three views

Three-view drawing method

Three views of simple geometry

Keywords: Free download of PPT courseware for mathematics in the second volume of the ninth grade of the People's Education Press, download of three-view PPT, download of projection and view PPT, .PPT format;

For more information about the "Projection and View Three Views" PPT courseware, please click the Projection and View PPT Three Views PPT tab.

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Update Time: 2024-09-17

This template belongs to Mathematics courseware People's Education Press Ninth Grade Mathematics Volume 2 industry PPT template

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