"Regular Polygons and Circles" Circle PPT Teaching Courseware

Description

"Regular Polygons and Circles" Circle PPT Teaching Courseware

Part One: 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 knowledge about regular polygons and circles to solve practical problems.

Regular polygons and circles PPT, part 2: independent learning

Independent learning tasks: Read pages 105-106 of the textbook and master the following knowledge points.

1. The relationship between the radius, central angle, apicocenter distance, and side length of a regular polygon

2. Apply knowledge about regular polygons and circles to solve practical problems

Independent learning feedback

1. The central angle of a regular octagon is equal to _______ degrees.

2. The ratio of the center distance to the side length of a regular hexagon is _______.

3. The radius of the circumcircle of a regular hexagon with side length 1 is _______.

4. As shown in the figure, ⊙O is the circumcircle of regular pentagon ABCDE, then ∠CAD=_______ degree

5. If the central angle of a regular n-sided polygon is equal to 24°, then the number of sides of this regular polygon is _______.

Regular polygons and circles PPT, the third part: new knowledge explanation

Definition and symmetry of regular polygons

Question 1 What is a regular polygon?

A polygon with equal sides and equal angles is called a regular polygon.

Question 2 Is a rectangle a regular polygon? Why? Is a rhombus a regular polygon? Why?

No, because a rectangle does not have all sides equal;

No, because the angles of a rhombus are not equal;

Question 3 Are regular triangles, regular quadrilaterals, regular pentagons, and regular hexagons all axially symmetric figures? Are they all centrally symmetrical figures?

Regular n-gons are all axially symmetrical figures with n axes of symmetry. Only regular polygons with an even number of sides are centrosymmetric figures.

The relationship between regular polygons and circles

Question 1 How to quarter a circle?

Question 2: What figure is obtained by connecting the equal points in turn?

Question 3: Just divide a circle into four equal parts and connect the equal points in order to obtain a regular quadrilateral. How can you prove this?

① The circumferential angle subtended by the diameter is equal to 90°

② The circumferential angles subtended by equal arcs are equal

Regular polygon and circle PPT, part 4 content: in-class detection

1. Fill in the form

2. If the ratio of the center distance to the radius of a regular polygon is 1:2, then the number of sides of this polygon is ______.

3. The picture shows the pattern of an Olympic Games commemorative coin. Its shape is approximated as a regular heptagon, and one interior angle is ___ degrees. (No approximations are taken)

4. To cut out a square iron piece with a side length of 4cm from a round iron piece, the diameter of the round iron piece should be at least ____cm.

Regular polygons and circles PPT, Part 5: Apply what you have learned

As shown in the figure, M and N are points on the regular polygons AB and BC inscribed in ⊙O respectively, and BM=CN.

(1) Find ∠MON=________ in picture ①; ∠MON=________ in picture ②; ∠MON=________ in picture ③;

(2) Try to explore the relationship between the degree of ∠MON and the number of sides n of the regular n-gon.

Regular polygons and circles PPT, Part 6 content: Class summary

Definition and symmetry of regular polygons

Related concepts and properties of regular polygons

①The sum of the interior angles of a regular polygon =

②Central angle =

Calculations related to regular polygons

How to add auxiliary lines: connect the radius and make the edge-center distance

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 Download:

"Regular Polygons and Circles" Circle PPT Download Part One Content: Famous Teacher's Key Knowledge Point 1 Regular Polygons and Circles As long as you divide a circle into equal arcs, you can make an inscribed regular polygon of the circle. This circle is the regular polygon of the circle. circumscribed circle. Note..

"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..

File Info

Update Time: 2024-09-06

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

Preview