Mathematical simulation test questions and answers in the next period of eighth grade
I. Fill in the blanks (30 points)
1. The condition of the proposition "the complementary angles of equal angles are equal" is _ _ _ _ _ _ _ _, and the conclusion is _ _ _ _ _ _ _ _.
2. If the inequality group has no solution, the value range of m is _ _ _ _ _ _ _ _.
3. Decomposition factor _ _ _ _ _ _ _ _.
4. As shown in the figure, DE∨BC, AD = 15cm, BD = 20cm, then _ _ _ _ _ _ _.
5. A factory has stored1100,000 tons of coal for 3 days. In order to use the coal stored for d days more than the scheduled time, it should save _ _ _ _ _ _ _ tons of coal every day.
6. The sum of three consecutive natural numbers is less than 15, and such a natural array * * * has _ _ _ _ _ _ _ _ groups.
7. It is most natural and appropriate for a TV host to stand in the prime time of the stage when hosting a program. If the length of the AB stage is 20m, it is more appropriate for the host to walk at least _ _ _ _ _ _ _ m from point A. ..
8. It is known that the fractional equation about x has an increasing root, so the value of k is _ _ _ _ _ _ _ _.
9. Simplify _ _ _ _ _ _ _.
10. Two students, A and B, scored the following in five math exams:
A: 89,85,965,438+0,95,90;
B: 98, 82, 80, 95, 95.
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
2. Multiple choice questions (30 points)
1. If it is a completely flat mode, the value of k is ().
A.6B。 6C。 12D。 12
There are 70,000 students taking the senior high school entrance examination in a city. In order to know the math test scores of these 70,000 students, the math scores of 1000 candidates were selected for analysis. The following statement is correct ().
A this 1000 candidate is a sample of this group. Each candidate is an independent individual.
C. this survey method is to investigate the math scores of D.7 thousand candidates as a whole.
3. The number of true propositions in the following propositions is ()
(1) Two right triangles with equal acute angles are similar.
(2) The hypotenuse and right-angled edge are similar to two proportional right-angled triangles.
(3) Any two rectangles must be similar.
(4) Two diamonds with equal internal angles are similar.
A. 1
4. It is known that if AB∨CD, ∠ D = 38 and ∠ B = 80, then ∠ P = ().
A.52 b . 42 c . 10d . 40
5. As shown in the figure, in △ABC, p is a point above AB, which has the following four conditions: (1) ∠ ACP = ∠ b; (2)∠APC =∠ACB; (3) ; (4)AB? CP=AP? The condition that CB, △APC and △ACB are similar is ()
A.( 1)(2)(3)b .( 1)(3)(4)
C.(2)(3)(4)d .( 1)(2)(4)
6.△ABC, BF and CF are angular bisectors, ∠ A = 70, then ∠ BFC = ().
A. 125 b . 100 c . 100d . 150
7. A classmate wants to measure the height of the flagpole. At a certain moment, he measured that the shadow length of a bamboo pole with a length of 1m was 1.5m when it was placed vertically. At the same time, when measuring the shadow length of the flagpole, because the flagpole is close to a building, all the shadows fall on the ground and some fall on the wall. He measured that the length of the shadow that fell to the ground was 2 1m, and the length of the shadow left on the wall was 0.
A. 12B。 16C。 10D。 15
8. Given CE⊥AD, ∠ A = 35 and ∠ C = 25, ∠ B = ().
A.25 B. 30 C. 35 D. 45
9. As shown in the figure, the quadrilateral ABCD is a parallelogram, so there are () pairs of similar triangles (except congruent triangles) in the figure.
A.2 to B.3 to C.4 to D.5.
10. When x = (), the value of the score is 0.
A.2B。 CD . 6
3. Painting problems:
Enlarge quadrilateral ABCD twice into quadrilateral by potential diagram method.
4. Answer the questions.
1. In an activity of measuring the height of flagpole, a group adopted the following scheme: AB stands for the distance from a classmate's eyes to the soles of his feet, CD stands for a pole, EF stands for a flagpole, and AB, CD and EF are all perpendicular to the ground. If AB = 1.6m, CD = 2m, the distance between people and poles BD = 1m, and the distance between poles and flagpoles DF = 30m, find the height EF of flagpoles.
2. In order to let students know about environmental protection knowledge and enhance their awareness of environmental protection, a middle school held an "environmental protection knowledge competition", in which 900 students participated. In order to know the results of this competition, some students' scores (scores are integers, full marks are 100) are selected for statistics.
(1) Please fill in the form according to what you have learned.
Packet frequency
50.5~60.5 4 0.08
60.5~70.5 0. 16
70.5~80.5 10
80.5~90.5 16 0.32
90.5~ 100.5
Total 50 1.00
3. As shown in the figure, in △ABC, d is a point on BC, and it is known that AC = 15, BC = 9 and CD = 3. Find a point e on AC to make △CDE similar to the original triangle and prove it. (sketch is needed)
4. Known ∠ 1+∠ 2 = 180, verified: ∠ 3 = ∠ 4.
Tucki and Xiao Kai both live 3.6 kilometers away from the school. They set off for school at the same time. Tucki left 100 meters, and found that he forgot to bring his exercise book, so he immediately returned and went to school from A with his exercise book. As a result, they both arrived at school at the same time, knowing that Tucki walked 0.5 kilometers more than Xiao Kai, and asked their speed?
Test answer
1. Fill in the blanks.
1. If two angles are equal, then their complementary angles are also equal.
2.
3.
4.9:40
5.
6.3 Prompt: (1, 2,3) (2,3,4) (3,4,5)
7.
8. 1
9.
10. A, B
2. multiple choice questions.
1.D2。 D3。 C4 explosive. b5。 A
6. A seven. b8。 B9。 d 10。 B
3. Drawing questions.
∴ Quadrilateral A'B'C'D is what you want.
4. Answer the questions.
1. solution: a is AM⊥EF, CD, EF is n and m.
∵AB⊥BF,CD⊥BF,EF⊥BF
∴∠B=∠D=∠F=∠ 1=90
∴ Quadrilateral ABDN, DFMN and ABFM are all rectangles.
∴ab=dn=fm= 1.6,an=bd= 1,nm=df=30
∫CD∨EF
∴CN∥EM
∴∠ACN=∠E
∫∠2 =∠2 Here we go again.
∴△ACN∽△AEM
∴
∴EM= 12.4
∴EF= 14(m)
A: EF = 14m.
2.8,0.2, 12,0.24
3. change ED∑AB and AC into e.
∴∠ 1=∠A
∫∠ c = ∠c again
∴△ECD∽△ACB
4. Syndrome: ∫≈ 1+∠2 = 180.
∠∠2 =∠5
∴∠ 1+∠5= 180
∴a∥b
∴∠3=∠4
5. Solution: Let the speed of Xiao Kai be x km/h and that of Tucki be km/h.
Solution:
After testing, it is the solution of the original equation.
Attendant: The speed of Tucki is 9.5 km/h, and that of Xiao Kai is 9 km/h. ..