"Sides of a Triangle" PPT courseware

Description

"Sides of a Triangle" PPT courseware

Part One: Triangle Analysis

Triangle: A figure composed of three line segments that are not on the same straight line connected end to end.

Representation of triangle: Triangle ABC in the picture is recorded as: "△ABC" and pronounced as: "Triangle ABC"

A triangle has three sides, three vertices, and three interior angles

As shown in the figure: The three sides in △ABC are: AB, BC, AC

The three vertices are: A, B, C

The three interior angles are: ∠A, ∠B, ∠C

Note: The three sides can also be represented by lowercase letters a, b, c.

Definition of exterior angle: The angle formed by one side of a triangle and the extension of the other side is called the exterior angle of the triangle.

Think: How many exterior angles does a triangle have?

Conclusion: A triangle has 6 exterior angles

Part 2 content: Classroom exploration

Research: Prepare a set of small rods with lengths of 3cm, 4cm, 6cm and 8cm, take out 3 rods and connect them end to end to construct a triangle.

1. How many ways are there to pick any 3 roots? list them

2. Try to see which group connected end to end can form a triangle

3. In a set of small wooden sticks that can form a triangle, what is the relationship between the length of every two sticks and the length of the third stick? What about those that cannot form a triangle?

4. Could you please try it with small wooden sticks of other lengths to check whether your conclusion is correct?

in conclusion:

The sum of two sides of a triangle is greater than the third side

The difference between the two sides of a triangle is less than the third side

Sides of Triangle PPT, Part 3: Example Study

For example, can three line segments with lengths 6, 8, and 10 form a triangle?

Solution: Because 6+8>10, 6+10>8, 8+10>6.

Therefore, it is consistent with "the sum of any two sides of a triangle is greater than the third side."

Therefore, three line segments with lengths 6, 8, and 10 can form a triangle.

Find fault

Can three line segments with lengths 2, 4, and 6 form a triangle?

Solution: Because 6+4>2,6+2>4,

Therefore, it is consistent with "the sum of any two sides of a triangle is greater than the third side."

So can three line segments with lengths 2, 4, and 6 form a triangle?

It is known that the two sides of the triangle are 6 and 9 respectively. Find the value range of the third side?

Isosceles triangle: A triangle with two equal sides

Equilateral triangle: A triangle with three equal sides (also called an equilateral triangle)

Triangles are classified by sides:

triangle

oblique triangle

isosceles triangle

Equilateral triangle

Sides of Triangle PPT, Part 4: Judgment and Summary

judge:

1. A triangle with two equal sides is called an isosceles triangle. ( )

2. A triangle with only two equal sides is called an isosceles triangle. ( )

3. An equilateral triangle is an isosceles triangle. ( )

summary

1. Vertices, sides, interior angles and exterior angles of a triangle

2. Quantitative relationship between three sides

3. Classification of triangles according to sides

Keywords: Free download of Hebei Education Edition mathematics PPT courseware for seventh grade volume 2, PPT download of sides of triangle, .PPT format;

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"Sides of a Triangle" PPT:

"Side of a Triangle" PPT Part One Content: Introduction to the New Lesson Let's talk: What do you know about triangles? Pages 100-101 of the independent study textbook. Observation and thinking, what everyone talked about, continue to understand: 1. The concept of triangle 2. The sides of a triangle..

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Update Time: 2024-09-05

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

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