"Regular Polygons and Circles" PPT download

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"Regular Polygons and Circles" PPT download

Part One Content: Key Points, Focus on Test Points

1. The focus of this lesson is on the calculation methods of regular polygons, the calculation methods of the perimeter and area of ​​circles and simple combined figures.

2. The definition of a regular polygon: a polygon with all sides equal and all angles equal.

3. The relationship between regular polygons and circles (this is also the method of determining regular polygons)

Theorem: Divide the circle into n (n≥3) equal parts:

①The polygon obtained by connecting the points in sequence is an inscribed regular n-gon of this circle.

② Draw tangents to the circle through each point, and the polygon with the intersection of adjacent tangents as its vertex is a regular n-gon circumscribed to the circle.

Regular polygons and circles PPT, part 2: goal achievement

1. Among the regular triangles, regular pentagons, regular decagons and regular pentagons, the number of ones that are both axially symmetrical and centrally symmetrical is ( )

A. 1 piece B. 2 pieces C. 3 pieces D. 4 pieces

2. It is known that the side length of a regular hexagon is 4 cm, then its area is ( )

A.4√3 cm2 B.6√3 cm2

C.8√3 cm2 D.24√3 cm2

3. If the radius of the sector is 6 and the central angle is 150°, then the area and arc length of the sector are ()

A. 5π, 15π B. 10π, 5π

C. 1５π, 5π D. 30π, 15π

Regular polygons and circles PPT, the third part: summary of methods:

1. Calculation of regular polygons, usually constructing right triangles and solving right triangles.

2. When using different regular polygons to tessellate a regular polygon at a vertex, their side lengths must be equal. The sum of the interior angles of the regular polygons around a vertex is 360°.

3. The arc length formula and sector area formula can be memorized with the help of the circle circumference formula and the circle area formula.

Regular polygons and circles PPT, Part 4: Class training

1. (2004·Tianjin) If each interior angle of a regular polygon is equal to 120°, then it is ( )

A. Square B. Regular pentagon

C. Regular hexagon D. Regular octagon

2. (2003·Liaoning Province) As shown in the figure, in the concentric circles, the radii of the two circles are 2 and 1 respectively, ∠AOB=120°, then the area of ​​the shaded part is ( )

A.4π B.2π

C.4/3π D.π

Keywords: Free download of mathematics PPT courseware for the second volume of the ninth grade of Hebei Education Edition, regular polygon and circle PPT download, .PPT format;

For more information about the "Regular Polygons and Circles" PPT courseware, please click on the "Regular Polygons and Circles" ppt tab.

"Regular Polygons and Circles" PPT teaching courseware:

"Regular Polygons and Circles" PPT teaching courseware Part One: Regular Polygons Regular polygons: A polygon with equal sides and equal angles is called a regular polygon. For example, the conditions satisfied by a regular pentagon are AB=BC=CD=DE=EA A=B=C=D=E Regular n-sided polygon: If a..

"Regular Polygons and Circles" PPT courseware download:

"Regular Polygons and Circles" PPT courseware download Part One: Question Exploration Question 1. What kind of figure is a regular polygon? A polygon with equal sides and equal angles is a regular polygon. Question 2. Can you name a few common regular polygons? Question 3: Exactly many...

"Regular Polygons and Circles" PPT:

"Regular Polygons and Circles" PPT Part One Content: New Lesson Explanation Question: What is the relationship between regular polygons and circles? Thinking: Divide ⊙O into 5 equal arcs, and connect these equal points in sequence. What figure will you get? Why? We use the incircle to connect positive five..

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Update Time: 2024-10-14

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

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