"Area of ​​Triangles" Area of ​​Polygons PPT (Lesson 1)

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"Area of ​​Triangles" Area of ​​Polygons PPT (Lesson 1)

Part One: Learning Objectives

1. Enable students to understand and master the formula for calculating the area of ​​a triangle through hands-on operations.

2. Enable students to use the formula for calculating the area of ​​a triangle to calculate the area of ​​a triangle.

3. Let students experience the derivation process of calculation formulas and cultivate students' analytical reasoning ability.

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

How many types of triangles are divided into angles?

Remember what we learned about triangle classification?

Acute triangle Right triangle Obtuse triangle

What problem are the children in the picture on the right solving?

How to calculate the area of ​​the red scarf?

Can you convert the triangle into what you have learned...

Let's give it a try.

Let’s see what we can make of an obtuse triangle?

Two identical obtuse triangles can be combined to form a parallelogram.

Let's see if acute-angled triangles can be assembled into parallelograms?

Two identical acute-angled triangles can be combined to form a parallelogram.

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

1. The area of ​​the parallelogram below is 12 square centimeters. Find the area of ​​the colored triangle.

12÷2=6（cm²）

Answer: The area of ​​the colored triangle is 6cm².

2. The shape of a triangle ruler is as shown below. What is its area?

S=ah÷2

=12.5×7.2÷2

=90÷2

=45(cm2)

Answer: Its area is 45 square centimeters.

3. Do you recognize the following road traffic warning signs? What is the approximate area of ​​a sign in square decimeters?

9×7.8÷2≈36（dm²）

9×8÷2=36（dm²）

Answer: The area of ​​a sign is approximately 36 square decimeters.

4. The lawn should be planted in a triangular open space in the middle of the road (see the picture below). The price of 1m² lawn is 12 yuan. How much does it cost to grow this lawn?

Area of ​​Triangle PPT, Part 4 Content: Class Summary

1. Two identical triangles can be combined to form a parallelogram.

2. Area of ​​triangle = base × height ÷ 2

Expressed in letters as S=ah÷2

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

For more information about the "Area of ​​Polygons and Areas of Triangles" PPT courseware, please click on the Area of ​​Polygons PPT and Area of ​​Triangles PPT tag.

"Area of ​​Triangles" Area of ​​Polygons PPT free download:

"Area of ​​Triangles" Area of ​​Polygons PPT free download Part 1: Review old knowledge Calculate the area of ​​the parallelogram below. What types of triangles can be divided into angles? Acute triangle Right triangle Obtuse triangle ... ... ... Three..

"Area of ​​Triangles" Area of ​​Polygons PPT Free Courseware:

"Area of ​​Triangles" Area of ​​Polygons PPT Free Courseware Part One: New Lesson Introduction Calculate: The base of the red scarf is 28cm and the height is 25cm. What is its area in square centimeters? S=Bottom height 2 =28252 =350cm Answer: Its area is 350 square centimeters..

"Area of ​​Triangles" Area of ​​Polygons PPT Courseware (Lesson 2):

"Area of ​​Triangles" Area of ​​Polygons PPT Courseware (Lesson 2) Part One: Class Introduction 1. Create a learning situation for students to independently explore the calculation method of triangle area. 2. Be able to use formulas to calculate the area of ​​a triangle. 3. Solve some real life problems..

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Update Time: 2024-11-04

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

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