Mathematics teachers must write mathematics courseware before class, because the teaching plan is the basis for teachers to carry out teaching activities. The following is the first volume of the eighth grade mathematics courseware given to you by the New People's Education Edition. Welcome to read and browse!

New people's education printing plate eighth grade first volume mathematics courseware

learning target

1. Master the "corner edge" condition of triangle congruence.

2. Can use congruent triangles's conditions to solve simple reasoning and proof problems.

Learning focus

Discussion on the coincidence of two known angles.

learning disorder

Flexible application of proof of triangle congruence condition.

Learning method:

Research on Autonomous Learning and Group Cooperation

Learning process:

1. Review the past and learn new things:

1. How many methods have we learned to judge the congruence of two triangles? What are they?

A 12。 What are the possibilities of knowing the two corners and one side of a triangle? A

1. Two corners and their edges.

2. Opposite sides of two corners and one corner. Second, new lessons.

1. Read, think, draw and discuss.

Reading textbook P 100

The opposite sides of two angles and one angle correspond to the congruence of two triangles (which can be abbreviated as "corner edge" or "AAS"). Writing format: in △ABC and △A 1B 1C 1.

∴△ABC?△a 1b 1c 1(AAS)

2. Theorem proof

It is known that in △ABC and △DEF, ∠A=∠D, ∠B=∠E, BC=EF,

Verification: △ABC and △DEF

Proof: ∫∠A+∠b+∠C =∠D+∠E+∠F = 180.

∠A=∠D，∠B=∠E

∴∠A+∠B=∠D+∠E

∴∠C=∠F

In △ABC and △DEF,

Become BCEF

padre

∴△ABC≌△DEF(ASA).

The opposite sides of two angles and one angle correspond to the congruence of two triangles (which can be abbreviated as "corner edge" or "AAS").

Third, examples:

Reading textbook example:

Intravenous injection. Group cooperative learning

1. As shown below, D is on AB, E is on AC, AB=AC, ∠ B = ∠ C.

Proof: AD=AE.

In the picture below, if AE=BC, are these two triangles congruent? Please explain the reason. Bureau of Employees' Compensation.

D

Alternating current

②B3。 Textbook P 10 1 exercise 1, 2.3

Summary of verb (Verb's abbreviation) Evaluation and Reflection

1. In this lesson, we discussed the conditions of triangle congruence and found a rule to prove triangle congruence, which can be used to prove simple triangle congruence.

2. How many methods are commonly used to judge the congruence of two triangles? What are they?

① "SAS" axiom _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

② "Asa" theorem _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

③ "SSS" theorem _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

④ "AAS" theorem: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Intransitive verbs homework