"Calculation of arc length and sector area" PPT courseware 2

Description

"Calculation of arc length and sector area" PPT courseware 2

think about it

The radius of a round arch bridge is 30m, and the central angle of the circle subtended by arch AB is ∠AOB=90°. Can you find the length of arch AB?

Preparation before class

Divide the circumference into 360 equal parts, and the arc in each part is called an arc of 1°; the central angle subtended by the arc of 1° is called an angle of 1°.

Explore the Arc Length Formula

Let a circle be ⊙O and the radius be r.

1) What is the circumference of the circle?

2) If the circumferential angle is 360°, what is the length of the arc subtended by the central angle of 1°?

3) What is the length of the arc subtended by the central angle of n°?

practice

Exercise 1: As shown in the figure, it is known that the central angle of the sector is 150° and the arc length is 20πcm. Find the radius of the sector.

Exercise 2: As shown in the figure, the radius of a sector with a central angle of 60° is 10cm. Find the perimeter of this sector.

Replenish:

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

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

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?

Keywords: Calculation teaching courseware of arc length and sector area, Qingdao version ninth grade mathematics volume PPT courseware download, ninth grade mathematics slide courseware download, calculation of arc length and sector area PPT courseware download, .PPT format;

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

"Calculation of Arc Length and Sector Area" PPT courseware:

"Calculation of Arc Length and Sector Area" PPT courseware Teaching 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. Teaching focus and difficulty: Important...

File Info

Update Time: 2024-10-03

This template belongs to Mathematics courseware Qingdao Edition Ninth Grade Mathematics Volume 1 industry PPT template

Preview