"Using Triangle Congruence to Measure Distance" Triangle PPT Courseware 2

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"Using Triangle Congruence to Measure Distance" Triangle PPT Courseware 2

Review old knowledge

1. What are the necessary conditions to prove that two triangles are congruent?

(1) "SSS": Two triangles with three equal sides are congruent.

(2) "ASA": Two triangles whose two angles and their included sides are equal are congruent.

(3) "AAS": Two triangles whose two angles and the opposite side of one of the angles are equal are congruent.

(4) "SAS": Two triangles whose two sides and their included angles are equal are congruent.

think about it

As shown in the picture, two points A and B are located at both ends of a pond. Xiao Ming wants to use a rope to measure the distance between A and B, but the rope is not long enough. Can you help Xiao Ming design a solution to this problem?

1. State your design plan;

2. Can you use the knowledge you have learned to explain the reasons for your design?

1. As shown in the figure, to measure the distance between two opposite points A and B on both sides of the river, first take two points C and D on the vertical line BF of AB, so that CD = BC, and then determine the vertical line DE of BF. It can be proved that △ EDC≌△ABC, we get ED=AB. Therefore, the measured length of ED is the length of AB. The reason for determining △EDC≌△ABC is ()

A.SSS B.ASA C.AAS D.SAS

2. There are two points A and B at the foot of the mountain. It is necessary to measure the distance between points A and B. Pick a point O on the ground that can directly reach points A and B, connect AO and extend to C, so that AO=CO; Connect BO and extend to D, so that BO=DO, connect CD. We can get △ABO≌△CDO, CD=AB. Therefore, the measured length of CD is the length of AB. The reason for determining △ABO≌△CDO is ()

A.SSS B.ASA C.AAS D.SAS

Class summary

1.Knowledge

The purpose of using congruent triangles to measure distances is to change unmeasurable distances into measurable distances.

Basis: Properties of congruent triangles.

Key: Construct congruent triangles.

2.Method

(1) Use the extension method to construct congruent triangles;

(2) Construct congruent triangles using the vertical method.

3. Mathematical thinking

Establish the idea of ​​using triangle congruence to construct mathematical models to solve practical problems.

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For more information about the PPT courseware "Measuring the Distance of Triangles Using Triangle Congruences", please click the "Measuring Distances of Triangles Using Triangles Congruent PPT" ppt tag.

"Using Triangle Congruence to Measure Distance" Triangle PPT Courseware 4:

"Using Triangle Congruence to Measure Distances" Triangle PPT Courseware 4 Review: 1. What are the methods for determining that two triangles are congruent? 2. As shown in the figure, it is known that AO=CO and BO=DO. Prove: △ABO and △CDO are congruent. Prove: In △ABO and △CDO, AO=CO AOB= COD B..

"Using Triangle Congruence to Measure Distances" Triangle PPT Courseware 3:

"Using Triangle Congruence to Measure Distances" Triangle PPT Courseware 3 1. Review old knowledge 1. What are the necessary conditions to prove that two triangles are congruent? (1) SSS: Two triangles whose three sides are equal are congruent. (2) ASA: Two angles and their included sides are equal.

"Measuring distance using triangle congruence" Triangle PPT courseware:

"Using Triangle Congruence to Measure Distances" Triangle PPT courseware is as shown in the figure. Points A and B are located at both ends of a pond. Xiao Ming wanted to use a rope to measure the distance between A and B, but the rope was not long enough. An uncle helped him out. Here's an idea: First get one on the ground that can be straight...

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Update Time: 2024-11-02

This template belongs to Mathematics courseware Beijing Normal University seventh grade mathematics volume 2 industry PPT template

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