Intersecting line and parallel line

Answers to similar questions

1.

D

2.B

3.

B

4. solution: ∫DB∨FG∨EC,

∴∠BAG=∠ABD=60，∠GAC=∠ACE=36，

∴∠BAC=∠BAG+∠GAC=96。

∫AP is the bisector ∠BAC,

∴∠PAC=

∠BAC=48，

∴∠ PAG =∠ PAC -∠ GAC = 48-36 =12, that is, ∠ PAG = 12.

5. Solution: Extend the line segment CD in two directions, and AB and EF intersect at point M and point N respectively, as shown in the figure, then ∠ BMN = 90-∠ B, ∠ MNE = ∠ CDE-∠ E. 。

∫AB∨EF，

∴∠BMN=∠MNE，

∴90 -∠B=∠CDE-∠E，

That is, ∠ b+∠ CDE-∠ e = 90.

Extended question:

1.

C

2.

C

3.

D

4.

C

5.

70

6.

55

7.

90

8.

12

9.

forty-two

10.

30

1 1.

Solution: As shown in the figure, C is CK∨AB and D is DG∨AB.

∴∠ 1=∠B=25 ,∴∠2=45 -25 =20。

∫CK∨AB，DG∨AB，

∴CK∥DG，

∴∠2=∠3=20 ,∴∠4=30 -20 = 10 .

∫∠e = 10，

∴∠4=∠E，

∴GD∥EF,∴AB∥EF.

12.

( 1) 180(2)360(3)540(4)

(4) According to the above law, it is obvious that if (n- 1) straight lines parallel to AB are used for (n- 1) times, so that the two straight lines are parallel to each other and the internal angles on the same side are complementary, the sum of n angles is (n- 1) 180.