"Preliminary Understanding of Polygons and Circles" Basic Plane Graphics PPT Download

Description

"Preliminary Understanding of Polygons and Circles" Basic Plane Graphics PPT Download

Part One: Learning Objectives

1. Understand the concept of polygons and know that triangles, quadrilaterals, pentagons, hexagons, etc. are all polygons.

2. Master the concepts of vertices, sides, interior angles, diagonals, and regular hexagons of polygons.

3. Understand the definition of a circle from the perspective of motion and master the concepts of arc, central angle, and sector.

4. Divide the circle into sectors, be able to understand the relationship between the area of ​​each sector and the area of ​​the entire circle, and be able to find the central angle of the sector.

Preliminary understanding of polygons and circles PPT, part 2: independent learning feedback

1. Starting from a vertex of a heptagon, connect this point to the other vertices.

point, you can divide a heptagon into several triangles ()

A.6B.5C.8D.7

2.The total number of diagonals of a heptagon is ( )

A.Article 12 B.Article 13 C.Article 14 D.Article 15

3. As shown in the figure, the following figures are polygons with __________ (fill in the serial number).

4. It is known that the central angle of the sector is 60° and the radius is 6, then the area of ​​the sector is ( )

A.24π B.12π C.6π D.2π

Preliminary understanding of polygons and circles PPT, the third part: new knowledge explanation

Exploration point 1: Understanding polygons

Activity 1: Read the textbook content and think about:

What kind of shape is called a polygon? What kind of line segment is called a diagonal?

[Comment] A closed plane figure composed of several line segments that are not on the same straight line connected end to end is called a polygon. Triangles, quadrilaterals, pentagons, hexagons, etc. are all polygons. A line segment that connects two non-adjacent vertices of a polygon is called a polygon. Diagonals of a polygon.

[Group Discussion 1] (1) How many vertices, sides, and interior angles does an n-sided polygon have?

(2) How many diagonals are there through each vertex of the n-sided polygon?

[Summary] The number of vertices, sides, and interior angles of an n-sided polygon are all n. How many diagonals can be drawn from one vertex of an n-sided polygon? How many diagonals does an n-sided polygon have in total? An n (n>3) polygon can draw (n-3) diagonals from one vertex, dividing the n-gon into (n-2) triangles. An n-gon has a total of diagonals.

Preliminary understanding of polygons and circles PPT, part 4: Do it

1. In the figure shown in the figure, how many are polygons ( )

A.3 B.4 C.5 D.6

2.The total number of diagonals of a heptagon is ( )

A.Article 12 B.Article 13 C.Article 14 D.Article 15

[Analysis] Choose C. There are a total of 14 diagonals of the heptagon.

Exploration point 2: Understanding regular polygons

Activity 2: Observe the polygons in the picture below. What are the characteristics of their sides and angles? Communicate with peers.

[Group Discussion 2] What kind of shape is the polygon like above? Can you name them one by one?

[Summary] All the polygons above are regular polygons, that is, polygons with equal sides and equal angles are called regular polygons. The polygons in the above figure are equilateral triangles, regular quadrilaterals (squares), regular pentagons, regular hexagons, and regular octagons. polygon.

Preliminary understanding of polygons and circles PPT, Part 5: In-class detection

1. A polygon can have up to three diagonals drawn from a vertex. This polygon is ( )

A. Triangle B. Quadrilateral

C. Pentagon D. Hexagon

2 In the same circle, the ratio of the areas of sectors A, B, C, and D is 2:3:3:4, then the central angle of the largest sector is ( )

A. 80° B. 100°

C. 120° D. 150°

3. As shown in the figure, it is part of the statistical map of the earth's surface area. Sector A represents the area of ​​certain types of water on the earth. The central angle of this sector is _________ degrees.

4. Each polygon can be divided (the division method is as shown in the figure) into several triangles. According to this method, the octagon can be divided into ________ triangles. Using this method, the n-sided polygon can be divided into ________ triangles.

Preliminary understanding of polygons and circles PPT, Part 6 content: Class summary

1. Polygon: A closed plane figure composed of several _______________ line segments starting and ending with _________.

2. Diagonal of a polygon: A line segment connecting two vertices of a polygon.

3. Regular polygon: A polygon with each side _____ and each angle _____.

4. Circle: On the plane, a line segment is formed by _________ around one of its fixed endpoints and the other endpoint.

5. Arc: The part between any _____ on the circle is called an arc, or ___ for short.

6. Sector: A figure composed of an arc and two _____ passing through the endpoints of this arc.

7. Central angle: the angle whose vertex is at _____.

8. The area formula of a sector: the area of ​​a sector with a central angle of n° and a radius of R is ______.

Keywords: Free download of Beijing Normal University version of seventh grade mathematics volume PPT courseware, preliminary understanding of polygons and circles PPT download, basic plane graphics PPT download, .PPT format;

For more information about the "Preliminary Understanding of Basic Plane Figures Polygons and Circles" PPT courseware, please click the "Basic Plane Figures PPT Preliminary Understanding of Polygons and Circles" PPT tag.

"Preliminary Understanding of Polygons and Circles" Basic Plane Graphics PPT Teaching Courseware:

"Preliminary Understanding of Polygons and Circles" Basic Plane Graphics PPT Teaching Courseware Part One Contents: Learning Objectives 1. Understand related concepts such as polygons, regular polygons, circles, sectors, etc. (Key Points) 2. Be able to find sectors based on the relationship between sectors and circles The measure of the central angle of a circle. (Difficult..

"Preliminary Understanding of Polygons and Circles" Basic Plane Graphics PPT:

"Preliminary Understanding of Polygons and Circles" Basic Plane Figures PPT Part 1 Content: Knowledge Points Basic Knowledge Points 1 Polygons and their Concepts 1. Which of the following statements is incorrect (C) A. Triangle, quadrilateral, pentagon, hexagon They are all polygons B. Regular polygons..

File Info

Update Time: 2024-07-22

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

Preview