"Regular Polygons and Circles" Circle PPT download

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"Regular Polygons and Circles" Circle PPT download

The first part: the famous teacher’s eye-catching

Knowledge point 1: Regular polygons and circles

As long as a circle is divided into equal arcs, the inscribed regular polygon of the circle can be made. This circle is the circumcircle of the regular polygon.

Note: Any regular polygon has a circumscribed circle and an inscribed circle, and these two circles are concentric circles.

Knowledge point 2 Concepts related to regular polygons

The center of a regular polygon: the center of the circumcircle of a regular polygon.

Radius of a regular polygon: the radius of the circumscribed circle of a regular polygon.

Central angle of a regular polygon: The central angle of the circumcircle subtended by each side of the regular polygon.

The distance between the sides of a regular polygon: the distance from the center of the regular polygon to one side of the regular polygon.

Regular polygons and circles PPT, part 2: basic pass

1. For a regular polygon, which of the following statements is incorrect ()

A. A regular polygon is an axially symmetrical figure, and the perpendicular bisector of each side is its axis of symmetry.

B. A regular polygon is a centrally symmetrical figure, and the center of a regular polygon is its center of symmetry

C． Each exterior angle of a regular polygon is equal to the central angle of the regular polygon

D． Each interior angle of a regular polygon is complementary to the central angle of the regular polygon

2. The diameter of a one-yuan coin is about 24 mm, so the maximum side length of a regular hexagon that can be completely covered by it cannot exceed ()

A. 12 mm B. 123mm

C． 6 mm D. 63mm

3． It is known that the area of ​​a regular hexagon inscribed in a circle is 3, then the distance between the sides of the regular hexagon inscribed in the circle is ()

A. 2B． 1

C． 3D． 32

Regular polygon and circle PPT, part three: ability improvement

10． If a triangle is constructed with the three sides of the inscribed equilateral triangle, square, or regular hexagon of a circle with a radius of 2, then the area of ​​the triangle is ()

A. 22B． 32

C． 2 D. 3

11． [Error-prone question] If AB is a side of a regular pentagon inscribed in ⊙O, and AC is a side of a regular hexagon inscribed in ⊙O, then ∠BAC is equal to ____________________.

12. [Zhejiang Wenzhou High School Entrance Examination] Xiao Ming found that when the camera shutter was opened, the aperture size changed as shown in Figure 1, so he drew the graph as shown in Figure 2. In Figure 2, six quadrilaterals with the same shape and size form a regular hexagon inscribed in a circle and a small regular hexagon. If the straight line where PQ passes through point M, PB = 5 cm, the area of ​​the small regular hexagon is 49 √3/2 cm2, then the radius of the circle is ______cm.

Regular polygons and circles PPT, part 4: thinking training

15． [Core Literacy Question] As shown in the figure, M and N are the points on the sides AB and BC of the regular triangle ABC, the square ABCD, the regular pentagon ABCDE,..., the regular n-gon ABCDE... inscribed in ⊙O, and BM =CN, connect OM, ON.

(1) Find the degree of ∠MON in Figure 1;

(2) Find the degree of ∠MON in Figure 2 and the degree of ∠MON in Figure 3;

(3) Explore the relationship between the degree of ∠MON and the number of sides n of the regular n-gon in the figure n.

Solution: (1) In Figure 1, connect OB and OC. ∵∠BOC=2∠BAC=120°, OC=OB, ∴∠OBC=∠OCB=30°, ∴∠OBM=∠OCN=30°. In △OMB and △ONC, ∵OB=OC, ∠OBM ＝∠OCN, BM＝CN, ∴△OMB≌△CNO, ∴∠BOM＝∠CON, ∴∠BOM＋∠BON＝∠CON＋∠BON, ∴∠MON＝∠BOC＝120°.

Keywords: Free download of PPT courseware for mathematics in the first volume of the ninth grade of the People's Education Press, download of regular polygon and circle PPT, download of circle PPT, .PPT format;

For more information about the "Circle Regular Polygon and Circle" PPT courseware, please click the Circle PPT Regular Polygon and Circle PPT tab.

"Regular Polygons and Circles" Circle PPT teaching courseware:

"Regular Polygons and Circles" The first part of the circle PPT teaching courseware content: Learning objectives: Understand the concepts of regular polygons and circles; understand and master the relationship between the radius, central angle, side center distance and side length of regular polygons. Be able to apply regular polygons Solving knowledge about circles...

"Regular Polygons and Circles" Circle PPT Courseware:

"Regular Polygons and Circles" Circle PPT Courseware Part One Content: Learning Objectives 1. Understand the relevant concepts of regular polygons and circles. 2. Understand and master the relationship between the radius and side length, edge-center distance, and central angle of a regular polygon. (Key Points) 3. Master the inner part of a circle using bisecting circles..

"Regular Polygons and Circles" Circle PPT:

"Regular Polygons and Circles" Circle PPT Part One Content: Knowledge Objectives 1. By constructing regular polygons inscribed in circles and self-study textbooks, we can understand the relevant concepts of regular polygons, and be able to derive calculation formulas related to circles and regular polygons, and perform related calculations. 2. pass..

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Update Time: 2024-09-26

This template belongs to Mathematics courseware People's Education Press Ninth Grade Mathematics Volume 1 industry PPT template

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