1, (1) in □ABCD, ∠A=44, then ∠B=, ∠C=.
(2) If the circumference of □ABCD is 40cm and AB:BC=2:3, then CD=, AD=.
2. If the side length of the cube is expanded by 2 times, the volume will also be expanded by 2 times.
Enlarge the volume of a ball by 27 times, and the radius will be enlarged by 10 times.
3. The side length of a square with diagonal length of 2 is: Its area is.
4. Simplification: (1) (2), (3) = _ _ _.
5. Estimation: (1) _ (error is less than1), (2) _ (accurate to 0. 1).
The square roots of 6 and 5 are, the square root of 0 is, and the cube root of -8 is.
7. As shown in figure 1, 64 and 400 are square areas respectively, then the square area represented by the letters in the figure is.
8. As shown in Figure 2, the length of the unknown side of the right triangle =.
9. As we all know, a triangle with three sides is a triangle.
10, the minute hand on the clock rotates around the axis. /kloc-After 0/5 minutes, the minute hand angle is.
1 1, as shown in Figure 3, right-angled trapezoid, ∠ b = 90, AD ‖ BC, AB = BC = 8, CD = 10, then the area of the trapezoid is.
12. As shown in Figure 4, given that AC = AD and ∠ B = 72 in ABCD, ∠ AC=AD = _ _ _ _ _ _ _
13. In Figure 5, how did Figure A become Figure B: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
14. You can spell _ _ _ _ _ _ _ kinds of parallelograms with two identical trigonometric rulers (the one with an angle of 30).
Second, multiple-choice questions (15 ~ 25 questions, 2 points for each question, ***22 points)
15, which of the following movements belongs to rotation is ()
A. Basketball in the process of rolling B. Pendulum swing of clocks and watches
C. the movement of the balloon in the air D. the process of folding a figure in half along a straight line
16, as shown in Figure 6, is a rectangular concrete playground in our school. If a student wants to walk from Angle A to Angle C, he should at least walk ().
140
17, the following statement is true ()
A. rational numbers are only finite decimals. Irrational numbers are infinite decimals
C. infinite decimals are irrational numbers. D. scores
18. Among the following conditions, the condition that a quadrilateral ABCD cannot be judged as a parallelogram is ().
A.AB‖CD，AB=CD B. AB‖CD，AD‖BC
C.AB=AD，BC=CD D
19, in the following array, the number that is not Pythagoras is ().
A 3、4、5 B 9、 12、 15 C 7、24、25 D 1.5、2、2.5
20. The number one-to-one corresponding to the points on the number axis is ()
A. natural number B. rational number C. irrational number D. real number
2 1. Xiaofeng's mother bought a 29-inch (74 cm) TV set. The following statement is about 29 inches.
The correct one is ()
A. Xiaofeng thinks it refers to the length of the screen; B Xiaofeng's mother thinks it refers to the width of the screen;
C. Xiaofeng's father thinks it refers to the circumference of the screen; D. The salesman thinks it refers to the diagonal length of the screen.
22. Xiaogang intends to measure the depth of a river. He inserted a bamboo pole at the bottom of the water 1.5m from the shore. The bamboo pole is 0.5m higher than the water surface, and the top of the bamboo pole is pulled to the shore. The top of the pole is just flush with the water on the shore, so the depth of the river is ().
A.2m； B. 2.5mC. 2.25mD. 3m。
23, diagonal vertical and equal quadrilateral must be ().
A, square b, rectangle c, diamond d, whose shapes cannot be determined.
24, the following statement is incorrect ()
The square root of A. 1 is1B. The cube root of–1is-1.
C is the square root of 2. D.–3 is the square root.
25, the length of the two diagonal lines and one side of the parallelogram can be taken in turn ().
A.B. 6，4，3 C. 6，4，6 D. 3，4，5
III. Answers (26 ~ 33 questions ***50 points)
26.(4 points) Fill in the following figures in the corresponding set (only fill in the serial number).
( 1)3. 14(2)- (3)- (4) (5)0
(6) 1.2 122 1222 1… (7) (8)0. 15
Irrational number set {…};
Rational number set {…}
27. Simplification (3 points for each small question *** 12 points)
( 1).(2).
(3).(4).
28, painting questions (6 points)
As shown in the figure, the side length of each small square in the square grid is 1, and some line segments can be obtained by arbitrarily connecting the vertices of these small squares. Please draw such a line segment in the picture.
29.(5 points) Use 250 square floor tiles of the same size to pave a living room of 40 square meters. What is the side length of each square floor tile?
30.(5 points) When a fire broke out in a high-rise residential building, the fire truck immediately rushed to the place 9 meters away from the building (from the back of the building to the wall of the building) and lifted the ladder to the fire window, as shown in the figure. It is known that the length of the ladder is15m, and the bottom of the ladder is 2m from the ground. How high is the window of the household where the fire broke out?
3 1, (6 points) Xiaozhen came up with a method to measure the width AB of the pond: first, draw two straight lines AC and BC from both ends A and B of the pond to intersect at point C, then take two points E and G from BC to make BE = CG, and then pass E and G as EF‖GH‖AB, and AC intersects at f and h to measure EF. Why?
32.(5 points) Given the quadrilateral ABCD, choose any combination of three conditions from the following conditions to make the quadrilateral ABCD rectangular, and write all the situations: (only fill in the serial number)
( 1)AB‖CD(2)BC‖AD(3)AB = CD(4)∩A =∩C(5)∩B =∩D
(6)≈A = 90(7)AC = BD(8)≈B = 90(9)OA = OC( 10)OB = OD
Please write five groups,
Mathematics Mid-term Examination of Grade Eight (Part Two)
1. Multiple choice questions (3 points for each question) 1. The following calculation is correct.
A.B. C. D。
2. the image of the proportional function y=( 1-2m)x passes through points a (a, b) and b (c, d). When a < c, b > d, the value range of m is
A.B. C. D。
3. A factory received an order to process 720 pieces of clothes, and it is estimated that 48 pieces will be made every day, which will be completed on time. After that, due to customer requirements, delivery will be made five days in advance. If X pieces are to be made every day, then X should satisfy the following equation.
A.— B. C. D. =5
4. If A, B and C are three sides of a triangle, the value of the algebraic expression.
A. It must be positive B. It must be negative C. It may be positive or negative D. It may be zero.
5. If the solution of the equation about X is positive, the value range of A is
A.a >- 1b.a >- 1 and A ≠ 0 C.A
6. If is, the value is a.b.c.d.
Fill in the blanks (3 points for each question) 7. If the solution set of inequality (A+ 1) x < A+ 1 is X > 1, then a must satisfy;
If the inequality ≤0 has three positive integer solutions, the value range of is.
8. 120 matches are connected end to end to form a triangle with unequal sides. If the maximum side length is three times the minimum side length, the minimum side uses the root.
9. Factorization: (1) =; (2) = .
10. If known, the value of the algebraic expression is.
1 1. If the fractional equation about has no solution, then.
12. If the polynomial is completely flat, then m =；; known
13. When x _ _ _ _ _ _ _ _ _ the value of is zero; If the algebraic expression is meaningful, the value range of x is.
14. Museum tickets 10 yuan/person, and group tickets for more than 20 people (including 20 people) are 20% off. If there are less than 20 people, at least _ _ people can buy a group ticket for 20 people, which is cheaper than ordinary tickets.
15. As shown in figure 1, if the straight line passes through points and points and the straight line OA passes through the origin, the solution set of inequality can be obtained by directly observing the image.
16. Solve the inequality group and express the solution set on the number axis; 17. Calculation:
18. If and || are antonyms, simplify the algebraic expression first, and then find its value.
19. Solving the fractional equation: 20. Simplify the algebraic expression first,
Then choose a value of a and b that makes the original formula meaningful and substitute it for evaluation.
2 1. Rongchang Company wants to transport its100t goods to a certain place for sale. After consultation with Chen Chun Transportation Company, it is planned to rent six vehicles of two models, A and B, and use these six vehicles to transport all the goods at one time, in which each A vehicle can hold at most 16 tons of such goods, and each B vehicle can hold at most 65,438 tons of such goods. It costs 2450 yuan to rent two A cars and 1 B cars, and the rental fee for each car of the same model is the same.
(1) What are the charges for renting a car and renting a car?
(2) If Rongchang Company plans to rent a car no more than 5,000 yuan, how many car rental schemes does the company have by calculation? Please design it and work out the lowest rental fee.
22. China Resources Supermarket bought a batch of new apple varieties for trial sale with 5000 yuan. Due to the good sales situation, the supermarket allocated 1 1 000 yuan to buy this variety of apples, but this time the purchase price was higher than that in the trial sale, and the number of apples purchased was twice that in the trial sale.
(1) What is the purchase price per kilogram of this variety of apples at the trial sale?
(2) If the supermarket sells this variety of apples at the price of 7 yuan per kilogram, and after most of the apples are sold, the remaining 400 kilograms are sold at a 30% discount on the price, how much money will the supermarket make in these two apple sales?
Okay？ ╮ (╯ ▽ ╰) ╭, my hand hurts when I copy! ! !
No extra points? O(∩_∩)O hahaha ~
Thank you very much !