Download PPT courseware of "Side Development of Right Prism and Cone"

Description

Download PPT courseware of "Side Development of Right Prism and Cone"

Part One: Introduction to Scenarios

The expanded view of geometry is widely used in production time. Through the expanded view of geometry, three-dimensional models can be determined and made, and the side area and surface area of ​​related geometries can also be calculated. In this lesson, we will explore the relationship between right prisms and cones. Side view.

collaborative inquiry

Observe the three-dimensional shapes in the picture below. What do their shapes have in common?

In geometry, we call the above three-dimensional figure a right prism, where "edge" refers to the common edge of two faces, which has the following characteristics:

(1) There are two surfaces parallel to each other, and they are called bottom surfaces;

(2) The remaining faces are all rectangles, and they are called sides;

(3) The side edge (referring to the common edge of the two sides) is perpendicular to the bottom surface.

Side expansion diagram of right prism and cone PPT, part 2 content: Do it

Collect several right prism models, and then cut the sides along a side edge. Can their sides be unfolded into a flat figure? Are they rectangles?

Cutting the side of a right prism along a side edge can develop it into a plane figure. A plane figure like this is called the side development of a right prism. As shown in the figure below, it is the side development of a right square prism.

The side expansion view of a right prism is a rectangle, the length of this rectangle is the perimeter of the base of the right prism, and the width is the length (height) of the side edges of the right prism.

Side expansion diagram of right prism and cone PPT, Part 3: Examples

Example 1 The side view of a food packaging box is shown in the figure. Its base is a regular hexagon with side length 2. What shape is this packaging box? Try to find its side area based on the known data.

Solution According to the figure, we can see that the side of the packaging box is a rectangle, and we also know that the upper and lower bases are regular hexagons, so the geometry is a regular hexagonal prism (as shown in the figure).

From the known data, we can know that its base perimeter is 2×6=12, so its side area is 12×6=72.

2 As shown in the picture, Xiaogang uses a piece of fan-shaped cardboard with a radius of 24cm to make a conical hat (the seams are ignored). If the base radius of the conical hat is 10cm, then what is the area S of the fan-shaped cardboard? ?

Side expansion diagram of right prism and cone PPT, part 4 content: Class summary

1. The side expansion view of a right prism is a rectangle, its area = perimeter of the base of the right prism × height of the right prism.

2. Cone side area formula: S side = πrm (r is the base circle radius, m is the bus length)

3. Formula for the total area of ​​a cone: S = πrm+πr2 (r is the radius of the base circle, m is the length of the bus bar)

Side expansion diagram of right prism and cone PPT, Part 5: In-class training

The following figures are plane expansions of geometric bodies. Guess what three-dimensional figures the following expansions can be folded into, and indicate the shape of the enclosed geometry.

The side expansion view of a certain three-dimensional figure is as shown in the figure. Its base is an equilateral triangle, then this three-dimensional figure is ( )

(A) Triangular prism (B) Four prism (C) Triangular pyramid.

Keywords: Free download of mathematics PPT courseware for the second volume of the ninth grade of the Hebei Education Edition, PPT download of side expansion diagrams of right prisms and cones, .PPT format;

For more information about the PPT courseware "Side Developments of Right Prisms and Cones", please click on the Side Developments of Right Prisms and Cones PPT tab.

"Side expansion diagram of right prism and cone" PPT download:

"Side development diagrams of right prisms and cones" PPT download Part 1 content: Learning objectives: 1. Understand the side development diagrams of right prisms and cones, and further develop spatial concepts 2. Be able to use the knowledge of side development diagrams of right prisms and cylinders to solve problems Practical problems. observe ..

"Side development of right prism and cone" PPT courseware:

"Side Development of Right Prisms and Cones" PPT courseware Part One: Understanding of Right Prisms Observe the following three-dimensional figures. They are all right prism objects. Think about what characteristics their shapes have in common? 1. Understanding of right prism: It has the following characteristics..

"Side development of right prism and cone" PPT:

"Side Development of Right Prisms and Cones" PPT Part One Content: Cooperative Learning Please cut a cube paper box along some edges so that the six faces are connected together and developed into a plane figure. What kind of plane can you get? Graphics? After cutting the cube along some edges...

File Info

Update Time: 2024-07-03

This template belongs to Mathematics courseware Hebei Education Edition Ninth Grade Mathematics Volume 2 industry PPT template

Preview