The first volume (multiple choice questions ***36 points)
I. Multiple-choice questions *** 12 small questions, with 3 points for each small question. )
2. As shown in the figure, if point E is on the extension line of BC, it cannot be determined that AB‖CD is there.
A.∠3 =∠4b∠B =∠DCE
C.∠ 1=∠2.D.∠D+∠DAB= 180
3. The following four groups of values of x and y are solutions.
A.B. C. D。
4. The name of the mascot of China 20 10 Shanghai World Expo is "Haibao", which means "the treasure of the four seas".
After translation, the mascot "Haibao" in the picture can be translated into a picture.
(4 questions) A B C D
5. In the following questions, which of the three lines given cannot form a triangle?
A.4cm, 6cm,10cm B.5cm, 3cm, 4cm.
C.3cm，8cm， 10cm D.5cm，9cm，5cm
6. Given the equation, if you want to eliminate the unknown Y through addition and subtraction, you only need to
A.○ 1+○2 B.○ 1-○2×3
C.○ 1×2-○2 D.○2+○ 1×2
7. In the plane rectangular coordinate system, the ordinate of each point of the triangle is subtracted by 3, and the abscissa remains unchanged.
Compared with the original graphics.
A. it has been translated by 3 units to the right. B. it has been translated by 3 units to the left.
C.it has been translated into three units. D. it has been translated down by 3 units.
8. Place the right triangle with parallel sides of the cardboard as shown in the figure, and draw the following conclusions:
( 1)∠ 1=∠2; (2)∠3=∠4; (3)∠2+∠4=90 ;
(4) 4+5 =180. The correct number is
A. 1
C.3 D.4
9. In △ABC, ∠A=500, and the angle between the bisector of △ ABC and △ ∠ACB.
The degree of ∠BOC formed by the intersection of bisectors is
A.b . 1300 c . 1 150d . 250
10. For the following propositions:
(1) vertex angles are equal; ② Equal congruence angle; ③ Two right angles are equal; ④ Adjacent complementary angles are equal;
⑤ One and only one straight line is perpendicular to the known straight line;
The median line on one side of the triangle divides the original triangle into two triangles with equal areas.
Among them, * * * is a true proposition.
A.2 B. 3 C. 4 D.5
fill (up) a vacancy
13. Write a binary linear equation whose solution is, what you wrote is.
14. If the sum of the inner angles of a polygon is exactly equal to the sum of its outer angles, then the polygon is a polygon.
17. As shown in the figure, it is planned to draw water from the river into the pool A, first draw AB⊥CD, and then ditch along AB.
To make the open channel shortest, the basis of this design is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
18. the intersection of ED and BC after folding a rectangular piece of paper ABCD along EF.
Is that g, d and c are in the positions of m and n respectively, and if < EFG = 55, then
∠ 1=_______,∠2=_______.
Third, concentrate on solving a problem (this big problem is ***8 small problems, out of 66 points). Please read the questions carefully and think calmly. The solution should be written and said.
Explain and prove the process or calculation steps.
Scoring reviewer
20. (The full mark of this question is 6 points)
solve an equation
Scoring reviewer
Scoring reviewer
22. (The full mark of this question is 6 points)
As shown in the figure, it is known as the angular bisector of △.
Verification:
Please fill in the reasoning basis on the line below:
Prove:
∫ (known)
∴ ‖ ( ).
∴ ( ).
∵ is the angular bisector of △ (),
∴ ( ).
∴ ( ).
∵ ( ),
∴ ( ).
Scoring reviewer
24. (The full mark of this question is 8)
Xin Li bought two notebooks and four multi-purpose pens in the stationery store yesterday, and spent 14 yuan. Wang Kai is at the same price.
Ge bought two notebooks and three multi-purpose pens. 12 yuan. What is the unit price of notebook and multi-purpose pen?
25. (The full mark of this question is 8)
As shown in the figure, in δδABC, ∠ACB=900, ∠1= ∠ B.
(1) Try to explain that CD is the height of ABC;
(2) If AC=8, BC=6, AB= 10, find the length of CD.
1. A class of students went to buy exercise books together, and * * * bought 80 copies at a price of 205 yuan, including one in 3 yuan and one in 2 yuan. How many copies did A and B buy respectively?
Grade 7 students go to the park for a spring outing. If there are 45 people in each car, 15 people have no seats. If there are 60 people in each car, there happens to be 1 car. How many cars are there? How many students are there? If there are x cars and y students, can you list the equations to solve this problem? )
Take the exam and answer questions.
First, multiple-choice questions (3 points for each question, ***36 points)
The title is123455678911112.
A. B. C. D. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C. C
Fill in the blanks: (3 points for each question, *** 18 points)
13. There is no unique answer, such as: x+y=2, x-y=4, etc. As long as it meets the meaning of the question, you can score; 17. The shortest vertical line segment is 18.
Third, answer questions:
Solution: The original equation can be simplified as:
(3)+(4) ÷ 2，x=2。
[(3)-(4)]⊙2，y=0。
Therefore, the solution of the original equation is
22. Proof:
∫, (known)
∴‖. (Same angle is equal, two straight lines are parallel)
∴. (Two straight lines are parallel with equal internal angles)
∵ is the angular bisector of △, (known)
∴. (Angle bisector definition)
∴. (Equivalent substitution)
An outer angle of a triangle is equal to the sum of two non-adjacent inner angles.
∴. (Equivalent substitution)
24. Solution: The unit prices of notebook and multi-purpose pen are X yuan and Y yuan respectively.
According to the meaning of the question, you must
Solve it and get it.
A: The unit prices of notebook and multi-purpose pen are 3 yuan/Ben and 2 yuan/Ben respectively.
25: (1) proof: in δδACB
∫∠ACB = 900，
∴∠ A+∠ B = 90。 (2 points)
∫∠ 1 =∠B，
∴ ∠A + ∠ 1 =90。
∴∠ ADC = 90。 (3 points)
∴ CD is the height of Δ δABC. (4 points)
(2) Solution: ∫δABC's area = (AB×CD)÷2=(AC×BC)÷2. ( 1)
∴ AB×CD = AC×BC。 (2 points)
∫AB = 10，AC=8，BC=6，
∴ 10×CD = 8×6。
∴ CD = 4.8。 (3 points)
The length of the CD is 4.8. (4 points)