1.∠2=∠ 1=54? ∵A‖B∴∠4=∠ 1=54？ ∠2+∠3= 180? ∴∠3= 180? -54? = 126?

2.( 1)de‖bc∵∠ade=∠b∴de‖bc(2)∠c=∠aed=40？ ∵DE‖BC∴∠AED=∠C=40？

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1.36? Because the direction of the road after turning is the same, that is, parallel, and the angles of both turns must be equal.

2.∵AD‖BC∴∠A+∠B= 180？ ∴∠B= 180-∠A= 120？ ∵DC and AB may or may not be parallel ∴∠ The degree of D is uncertain.

3.( 1)∠2= 1 10? (2)∠3= 1 10? (3)∠4=70?

4.∠2=80? ∠3= 1 10? ∠4= 1 10? ∵A‖B∴∠ 1=∠2=80？ ∵A‖B∴∠3= 180？ -∠5= 1 10? ∵A‖B∴∠4=∠3= 1 10？

5.60?

6.( 1)C(2)C

7.∠3=∠ 1=45? ∠4=∠2= 122? ∠5= 180-∠2=58? ∠6= 180-∠4=58? ∠7= 180-∠ 1= 135?

8. (1) ?1= ∠2 ∠1and ∠ 2 are internal angles ∴ AB ∠ ef.

(2) De BC ∠ 1 and ∠B are congruent angles ∠3 and ∠C are congruent angles ∴1= ∠ B.

∠3=∠C

10.( 1) The center line and sideline of the basketball court are both intersecting lines and perpendicular lines.

Two side lines or two end lines are parallel lines (2) After the end lines are drawn, you can draw a vertical line with a triangle, and the drawn side lines are perpendicular to the end lines, that is, parallel.

1 1. Real proposition

false statement

false statement

false statement

12.( 1)≈DAB =≈B = 44(2)≈EAC =≈C = 57(3)≈BAC = 180-≈DAB-≈EAC = 79

13.∫ The mirror is parallel ∴∠ 2 = ∠∵∠1= ∠ 2, ∠2=∠3 =∞.