"Area of ​​Trapezoid" Area of ​​Polygon PPT (Lesson 2)

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"Area of ​​Trapezoid" Area of ​​Polygon PPT (Lesson 2)

Part One: Learning Objectives

1. Be able to use the trapezoidal area calculation formula to solve practical problems.

2. Cultivate students’ practical abilities in the process of exploration and learning.

3. Experience the fun of “re-creation” of mathematics and gain personalized development

[Important and difficult points] Solve practical problems of calculating the area of ​​more complex trapezoids.

Area of ​​trapezoid PPT, part 2: introduction of new knowledge

Think about it, how do we derive the formula for calculating the area of ​​a trapezoid?

I cut a trapezoid into two triangles.

Two identical trapezoids can be combined to form a parallelogram.

Area of ​​trapezoid = (upper base + lower base) × height ÷ 2

S = (a+ b)h÷2

Example: A part of the cross-section of the Three Gorges Hydropower Station dam in my country is a trapezoid (as shown below). Find its area.

S = (a+b)h÷2

=(36+120)×135÷2

= 156×135÷2

= 10530 (m²)

How to flexibly use the area formula of a trapezoid to solve problems?

According to the formula for calculating the area of ​​a trapezoid S = (a+b)h÷2, it can be deduced that h=S×2÷(a+b), a+b=2S÷h,

a=2S÷h-b, b=2S÷h-a.

Area of ​​Trapezoid PPT, Part 3: Classroom Exercises

1. The two pieces of glass on the side of a car are trapezoidal in shape (as shown below). What are their areas?

S = (a + b)h÷2

(40+71)×40÷2

=4440÷2

＝2220（cm²）

(45+65)×40÷2

=4400÷2

＝2200（cm²）

Answer: Their areas are 2220 square centimeters and 2200 square centimeters respectively.

2. The production team makes an airplane model. The plan view of the wing is composed of two identical trapezoids (as shown below). What is the area of ​​the wing?

(48+100)×250÷2×2

=148×250

＝37000（mm²）

Answer: The area of ​​the wing is 37,000 square millimeters.

Area of ​​trapezoid PPT, part 4 content: Class summary

According to the trapezoid area calculation formula S=(a+b)×h÷2, it can be deduced that h=S×2÷(a+b), a+b=2S÷h, a=2S÷h-b, b=2S ÷h-a

Keywords: Free download of PPT courseware for fifth grade mathematics from the People's Education Press, PPT download of the area of ​​a trapezoid, PPT download of the area of ​​a polygon, .PPT format;

For more information about the "Area of ​​Polygons and Areas of Trapezoides" PPT courseware, please click on the Area of ​​Polygons PPT and Area of ​​Trapezoid PPT tags.

"Area of ​​Trapezoid" Area of ​​Polygon PPT free download:

"Area of ​​Trapezoid" Area of ​​Polygon PPT Free Download Part One: Learning Objectives 1. Experience the exploration activities of trapezoid area and experience the application of cut and complement method in exploration. 2. Master the formula for calculating the area of ​​a trapezoid and be able to calculate the area of ​​a trapezoid correctly. 3..

"Area of ​​Trapezoid" Area of ​​Polygon PPT Free Courseware:

"Area of ​​Trapezoid" Free PPT Courseware on Area of ​​Polygon Part One: Exploring New Knowledge You can convert trapezoids into previously learned graphics. Compare the relationship between graphs before and after conversion. Thinking: 1. What is the relationship between the base of the parallelogram and the base of the trapezoid? (..

"Area of ​​Trapezoid" Area of ​​Polygon PPT courseware download:

"Area of ​​Trapezoid" Area of ​​Polygon PPT courseware download Part One: Classroom Introduction 1. Understand and master the formula for calculating the area of ​​a trapezoid, and be able to correctly apply the formula for calculation. 2. Through operations, cultivate everyone’s ability to transfer analogies and abstract generalizations. ..

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Update Time: 2024-11-06

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

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