"Arc Length and Area of ​​Sector" Circle PPT Courseware 4

Description

"Arc Length and Area of ​​Sector" Circle PPT Courseware 4

learning target

Experience the process of exploring arc length calculation formulas and sector area calculation formulas, understand the arc length calculation formulas and sector area calculation formulas, and be able to apply the formulas to solve problems.

Learning points

Arc length calculation formula and understanding,

Learning difficulties

Issues that should be paid attention to when using the arc length formula and the flexible use of the sector area formula

1. Communication Preview

1. Given that the radius of ⊙O is R, what is the circumference of ⊙O? What is the area of ​​⊙O?

C=2πR，S⊙O＝πR²

2.What is the central angle of a circle?

The vertex is at the center of the circle and the angle formed by the intersection of the two sides with the circle is called the central angle

3. What is a fan shape? What is the perimeter of a fan shape?

4. As shown in the figure, the radius of a rotating wheel on a certain conveyor belt is 10cm.

(1) How many centimeters will item A on the conveyor belt be transported in one rotation of the wheel?

(2) When the wheel rotates 1°, how many centimeters is the item A on the conveyor belt conveyed?

(3) When the wheel rotates n°, how many centimeters is the item A on the conveyor belt conveyed?

layering improvement

(1). The arc length of 1° is πR/180. In a circle with a radius of 10 cm, the arc length subtended by a central angle of 60° is 10π/3

(2). As shown in the figure, in the concentric circles, the radii of the large circle OA and OB intersect the small circles at C and D, and OC:OA=1:2, then the ratio of the length of arc CD to arc AB is ( )

(A) 1:1 (B) 1:2

(C) 2:1 (D) 1:4

3. The central angle of a sector is 90° and the radius is 2, then the arc length = π and the sector area = π.

4. The arc length of a sector is 20πcm and the area is 240πc�, then the central angle of the sector is 150°.

5. It is known that the central angle of the sector is 120° and the radius is 6, then the arc length of the sector is ( )

A. 3π B. 4π C. 5π D. 6π

Consolidate feedback

1. It is known that the central angle of the sector is 120° and the radius is 2, then the area of ​​this sector S sector = 4/3π.

2. It is known that the sector area is 1/3π and the central angle is 60°, then the radius of this sector is R=√2.

3. It is known that the arc length of a sector with a radius of 2cm is 4/3π, then the area of ​​this sector is S sector = 4/3π.

4. As shown in the figure, the cross-sectional radius of a horizontally placed cylindrical drainage pipe is 0.6cm, and the height of the water surface is 0.3cm. Find the area of ​​the water part on the cross-section. (accurate to 0.01cm).

Area of ​​the arc = S fan - S�

5: As shown in the figure, the cross-sectional radius of a horizontally placed cylindrical drainage pipe is 0.6cm, and the height of the water surface is 0.9cm. Find the area of ​​the water part on the cross-section. (accurate to 0.01cm).

Area of ​​the arc = S fan + S△

Keywords: circle teaching courseware, arc length and area of ​​sector teaching courseware, Beijing Normal University edition ninth grade mathematics volume 2 PPT courseware, ninth grade mathematics slide courseware download, circle PPT courseware download, arc length and sector area PPT courseware download ,.ppt format

For more information about the PPT courseware "Arc Length of a Circle and Area of ​​a Sector", please click on the Arc Length of a Circle and Area of ​​a Sector ppt tag.

"Arc Length and Area of ​​Sector" Circle PPT Courseware 3:

"Arc Length and Area of ​​Sector" Circle PPT Courseware 3 Create Situation and Present Goal When we practice shot put throwing in physical education class, we must do it in a designated circle. The diameter of this circle is 2.135m. What are the circumference and area of ​​this circle? (The result is accurate to 0.01) Perimeter..

"Arc Length and Area of ​​Sector" Circle PPT Courseware 2:

"Arc Length and Area of ​​Sector" Circle PPT Courseware 2 1. Teaching Objectives: Knowledge and Skill Objectives: ① Make students understand the essential difference in concepts of arc and sector, as well as the relationship between them; ② Master arc length and sector The formula for calculating area and how to simply apply it...

"Arc Length and Area of ​​Sector" Circle PPT Courseware:

"Arc Length and Sector Area" Circle PPT Courseware Learning Objectives 1. Experience the process of exploring the arc length calculation formula and sector area calculation formula. 2. Understand the arc length calculation formula and sector calculation formula, and be able to apply the formulas to solve problems. Learning Key Points and Difficulties Key Points: Experience...

File Info

Update Time: 2024-09-14

This template belongs to Mathematics courseware Beijing Normal University Ninth Grade Mathematics Volume 2 industry PPT template

Preview