Chapter IV Comprehensive Examination Questions (1)

1.B. 2.A. 3。 A. 4.C. 5.B

6 . d 7 . c 8 . c 9 . c 10 . c

1 1. There is only one straight line after two o'clock. 12.45,2700; 60, 1.

13. 15. 14.=. 15.4. 16. 130, 130.

17 ..18.12.19. (1) sketch; (2) vertical (or EF⊥GH).

20. Because A, O and B are on the same straight line ∠ AOB = 180.

Because ∠ BOC = 40, ∠ AOC = 140.

Because the outer diameter bisects ∠AOC, ∠ AOD = ∠ AOC = 70.

2 1.l & gtm> reason: among all the connecting lines between two points, the line segment is the shortest.

22.BM=2cm，MN=5cm。

23.( 1)∠EOD = 65； (2)∠BOC=50。

24.( 1) , ; (2) 1,3,6, 190, .

The fourth chapter comprehensive examination questions (2)

1.B. 2.A. 3.C

Six days, seven days, eight days and nine days 10 days.

1 1.36. 12.2. 13. 135 . 14.90 .

15.20 or 80. 16. 105.

17.( 1)90, 135, 135; (2) Vertical and horizontal 18. d .

19. As shown in the figure, A → B → EB → E.

20.( 1) sketch; (2) sketch;

(3)OA, the length of the line segment PC. Of all the line segments connected to each point on the line from a point outside the line, the vertical line segment is the shortest, with pH < PC < OC.

2 1.OB⊥OD.

Because OA⊥OC is at point O, ∠ 1+∠ BOC = 90.

Because ∠ 1=∠2, ∠ 2+∠ BOC = 90.

So OB⊥OD.

22. Ma Xiaohu's answer is incorrect. He ignored another situation, OA and OC are on the same side of OB.

The number of ∠AOC is 160 or 20.

23.( 1) Because DE bisects ∠ADB and intersects with AB at point E, ∠ 1=∠2.

Because DF⊥DE and AC intersect at point F, ∠ 2+∠ 3 = 90,

Because ∠ BDC = 180,

So ∠1+∠ 4 =180-(∠ 2+∠ 3) = 90.

So ∠3=∠4 So DF divides ∠ADC equally.

(2)∠4=39 30′.

24.( 1) Fill in 1, 2, 4, 7 from left to right.

(2) Regularly, the number difference is 1, 2, 3, ...

(3) When there are n straight lines, the plane is divided into (1+ 1+2+3+…+n) parts.

(4)4 knives.