People's Education Edition, Grade Seven, Volume Two, Mathematics Exercise Book, Chapter Five, Class Intersection Line 1 Answer

Answer: [knowledge combing] 1, male * * * side extension line

2, the vertex angles are equal

[homework] 1, d

2、C

3、? Freedom? AOF？ BOE

4、( 1) 50 130 (2) 20

5. Can you tell from the isocenter angle? DOB=？ AOC=28？ .

Because? DOE=？ Dobby, so? DOE=28？ .

Because? AOC+？ AOE+？ DOE= 180？ ,

So what? AOE= 124？ .

Because we broke up again? AOE, so? EOF= 1/2AOE=62？

[homework] 6, c

7、C

8、 144?

9、 190? 230?

10、 ( 1) 40?

(2) 60?

1 1、 150?

12, the vertex angles are equal from the opposite side, okay? DOB=？ AOC= 36？ .

Because? DOE:？ DOB=5:2, which can be set? DOE= 5x，？ DOB=2x，

So 2x=36? , so? = 18? .

So what? BOE=？ Is it? DOB=3x=54？ .

So what? AOE= 180？ -? BOE= 126？ 1

13, because oc is divided equally? EOG, so? ECC=？ Gulf Cooperation Council.

Because? ACG=？ Enemy, so? ACG+？ GCC=？ FOE+？ ECC。

So what? AOC-？ FOC again. for what? BOD= 56？ ,

So what? FOC=？ AOC=？ BOD=56？