"The Median Line of a Triangle" PPT courseware

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"The Median Line of a Triangle" PPT courseware

Part One Content: Learning Objectives:

1. Master the concept of the median line of a triangle and its theorem.

2. Be able to apply the concept and theorem of the median line of a triangle to perform relevant proofs and calculations.

3. Feel the connection between triangles and quadrilaterals, and improve your ability to analyze and solve problems.

Key points: The concept of the median of a triangle and the median of a triangle theorem.

Difficulty: Proof of the triangle median theorem.

Self-learning

1. Self-study textbook pages 130-----132.

2. What are the properties of the median line of a triangle.

3.Will you prove it?

Median line of triangle PPT, part 2 content: Let’s explore together

The line segment connecting the midpoints of both sides of a triangle is called the median of the triangle

A triangle has three median lines

The median of a triangle is different from the median of a triangle

(1) Similarities - they are all related to the midpoint of the side;

(2) Differences:

The two endpoints of the median line of a triangle are the midpoints of the sides;

The midline of a triangle has only one endpoint which is the midpoint of the side and the other endpoint which is the vertex of the triangle.

Median line of triangle PPT, the third part: first test of skills

Exercise 1. As shown in the figure, in △ABC, D and E are the midpoints of AB and AC respectively.

If ∠ADE=65°, then ∠B= degrees, why?

If BC=8cm, then DE= cm, why?

If AC=4cm, BC=6cm, AB=8cm, then the perimeter of △DEF=______

If the perimeter of △ABC is 24, the perimeter of △DEF is _____

There are _____ parallelograms in the figure

If the area of ​​△ABC is 24, the area of ​​△DEF is _____

Inquiry activities

1. What is the relationship between the perimeter of the triangle surrounded by the three median lines of the triangle and the perimeter of the original triangle?

2. What is the relationship between the area of ​​the triangle surrounded by the three median lines of the triangle and the area of ​​the original triangle?

Median line of triangle PPT, part 4 content: Apply what you have learned

Apply what you learn

Known: As shown in the picture, A and B are separated by a pond. Without any measuring tools, Xiao Ming estimated the distance between A and B through learning: first choose a point C outside AB. , and then measured the midpoints M and N of AC and BC, and measured the length of MN. From this, he knew the distance between A and B. Can you tell the truth?

The reasoning is:

Link A, B,

∵MN is the median line of △ABC,

∴AB=2MN.

Apply what you learn 2

It is known that: in the quadrilateral ABCD, AD=BC, P is the midpoint of the diagonal BD, M is the midpoint of DC, and N is the midpoint of AB. Prove that ∠PMN=∠PNM.

Apply what you learn 3

Known: As shown in the figure, in the quadrilateral ABCD, E, F, G, and H are the midpoints of AB, BC, CD, and DA respectively.

Guess the shape of the quadrilateral EFGH and prove it.

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

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"Median Line of Triangle" PPT download:

"The Median Line of a Triangle" PPT Download Part One Content: Learning Objectives: 1. Explore and master the definitional properties of the median line theorem 2. Preliminarily use the triangle median line theorem to solve and reason. Feel the connection between triangles and quadrilaterals, and improve Problem solving skills. ..

"Midline of Triangle" PPT:

"The Median Line of a Triangle" PPT Part One Content: Knowledge Review Recall: (1) The median line of a triangle In a triangle, the line segment connecting a vertex and the midpoint of its opposite side is called the median line of the triangle. Look at the picture first, then think carefully and answer the questions: 1. Can you give three...

"The Median Line Theorem of Triangles" PPT Courseware 2:

"The Median Line Theorem of Triangles" PPT Courseware 2 A and B are separated by a pond. Now we want to measure the distance between A and B, but we cannot measure it directly. What should we do? In this class, we will explore a measurement method that seems impossible but can be accomplished..

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Update Time: 2024-07-08

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

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