Mathematics at the end of the eighth grade last semester? Volume A (*** 100) 1. Multiple choice questions? (This big problem has 10 small problems * *? 3 points for each small question? ***30)? 1. Rotate the pattern on the right 90 clockwise to get the pattern of () 2. Which of the following operations is correct () (A)4? 2 ? (B)3？ 3 ? (C)4？ 2 D？ 39? 33. The polygon with equal inner and outer angles is a triangle () (a)? (b) quadrilateral? (c) pentagonal d? Hexagon 4. In a plane rectangular coordinate system? Is the point in the second quadrant ()? (1)? 23(B)2？ 4 (C)？ 2? 3 (D)2？ 35, the following sets of data can be used as a right triangle three sides is () (a)? 2? 3? 4 ? (B)？ 5? 3? 4 (C)？ 4? 6? 9 ? (D)？ 5? 1 1? 13? 6. Known 1 1xy? Is equation 2? 3? 0x？ Mine? The solution? So the value of m is (? )? (1)? 1 (B)3？ (3)? 3 ? (D) 1？ 7. Which of the following figures? Is the figure with both axial symmetry and central symmetry () (a) regular triangle (b) parallelogram? (c) isosceles trapezoid? (d) square? 8. In a plane rectangular coordinate system? Straight line (? 0? 0)y？ kx？ b？ k？ B does not pass () (a) the first quadrant (b)? The second quadrant? (3)? The third quadrant? (D)？ The fourth quadrant? 9. as shown in the figure? Fold a rectangular piece of paper in half and then fold it again? Then cut it along the dotted line in the picture? Get parts ① and ②? (2) expand the plane figure is ()? (1)? Rectangular (b) parallelogram (c) trapezoid? (D)？ Diamond 10, as shown in the figure? In a plane rectangular coordinate system? What are the coordinates of vertices a, b and d of parallelogram ABCD? 0? 0? 、? 5? 0? 、? 2? 3 So the coordinate of vertex C is ()? (1) 3? 7 (B)5？ 3 ? (C)7？ 3 ? (D)？ 8? Second, fill in the blanks? (4 points for each small question? *** 16)? 1 1, if 22? 0x？ Y, and then x y _ _ _ _ _

12, if the two diagonal lines of a diamond are 6cm long? 8cm？ Its circumference is _ _ _ _ _ _ _ cm. ? 13, for linear function 2? 5y？ X if 1? 2x？ X so 1? 2____y？ y？ Fill in ">" and "?" 、“& lt？ . ? 14, the picture shows a part of the pattern densely paved with isosceles trapezoid with the same shape and size? Then the greater the internal angle of the isosceles trapezoid in the pattern is _ _ _ _ _ _. ? 3. (Question 15, 6 points for each small question? 16 6 points? *** 18)? 15. Solve the following problems (1)? Solve the equation? 2? 3 ? 3? 5? 1 1 x？ yx？ y？ ①② (2) Simplify? 0 1? 1 18? (? 1)? 4? (? 2? 1)2? 2 16, if 2? 53a？ Ba? B is 3a? b？ The arithmetic square root of? 2? 12 1a？ Ba is 2 1a? Cube root? Ask for 2? 3a？ b？ The square root of. ? (8 points for each small question? *** 16)? 17, known? As shown? At △ABC? D is a point next to BC? Link advertising? Take the midpoint e of AD? The parallel line with BC passing through point A intersects the extension line of CE at point F? Link DF. 1 verify? AF=DC？ 2 if AD=CF? Try to judge what kind of quadrilateral AFDC is. And prove your conclusion. ?

18, the regulation of a long-distance bus station? Passengers can carry a certain quality of luggage for free? If it exceeds this quality, do you need to buy a baggage claim tag? The baggage claim tag is y yuan? And the baggage quality X? Kilogram? The linear functional relationship between them is 5? (? 0)y？ kx？ K now knows that Beibei has 60 kilograms of luggage? Paid for the luggage, 5 yuan. 1? What should Jingjing do with 84 kilograms of luggage? How much should I pay for my luggage? 2? How many kilograms of luggage can a passenger carry for free at most? 5. (each small question 10 score? ***20 points)? 19, as shown in figure? It is known that AD is the center line of △ABC? ∠ADC？ 45 ? Fold △ABC in half along AD? Point c falls on point e? Connect BE? What if BC? 6 cm. 1? Find the length of BE? 2? When AD=4cm? Find the area of quadrilateral BDAE. ? ABCDE

20. as shown in the figure? In the plane rectangular coordinate system xOy? Linear function 1223y? x？ Intersect the x axis and the y axis at points a and b, respectively? Line 2? (? 0)y？ kx？ b？ k？ After point C? 1? 0? And intersect the AB line at point p? And divide △ABO into two parts, 1? Find the area of △ABO 2? If the areas of the two parts divided by the straight line CP are equal? Find the coordinates of point P and the functional expression of straight line CP. ? Volume B (***50 points)? 1. Fill in the blanks? (4 points for each small question? ***20 points)? 2 1, if the square root of a number is 3a? And second? 15a is a? _________。 ? 22, as shown in figure? In a plane rectangular coordinate system? The vertex coordinate of △ABC is A(3? 6)、B( 1？ 3)、? C(4？ 2)。 If △ABC rotates 90 clockwise around point C? Get delta a 'b 'c? Then the coordinates of point A' corresponding to point A are _ _ _ _ _ _ _. ? 23, when 3? 5x？ What time? Algebra 26? 10x？ x？ The value of is _ _ _ _ _ _ _. ? 24. In quadrilateral ABCD? Diagonal AC and BD intersect at point O? From where? ①AB=CD？ ②AB∨CD？ ③OA=OC？ ④OB=OD？ ⑤AC=BD？ ⑥∠ABC？ Of the six conditions of 90? Can you choose three extrapolated quadrangles? Is ABCD rectangular? For example, ① ②→ Quadrilateral ABCD is a rectangle? Please write two more that meet the requirements?

25. If the straight line is 3y? x？ p？ Use a straight line 2y? x？ q？ Are the images on the X axis at the same point? And then p? The relationship between q and is _ _ _ _ _ _ _. ? Second,? ***8: 26. What are the scores of 20 girls in Class 1, Grade 8 in a school in a physical education exam? 60 points? 70? 80? 90? 100? Number of people? Person 1? 5? x？ y？ 2? (1) What if the average score of these 20 girls is 82? Find the values of x and y (3) in? 1? In the case of? Let's assume that the mode of the scores of 20 students in this test is a? The median is b? Ask for 5a? b？ The value. ? Third,? *** 10 points 27, as shown in figure ①? At Rt△ABC? Known ∠ A = 90? AB=AC？ G and f are two points on AB and AC respectively? And GF∨BC? AF=2？ BG=4 . 1? Find the area of trapezoidal BCFG? 2? Is there a trapezoid DEFG that coincides with trapezoid BCFG? Fixed △ABC? Move the trapezoid DEFG to the right? Until point d and point c coincide? As shown in figure 2. (1) What if the quadrilateral BDG g is formed after a certain period of movement? DG⊥BG'？ Find the length of the movement distance BD? And find the value of 2G'B at this time ② Let the length of BD in motion be x? The area s of the overlapping part of trapezoid DEFG and Rt△ABC is expressed by an algebraic expression containing X.

Fourth,? *** 12 minutes 28, as shown in the figure? In the plane rectangular coordinate system xOy? It is known that the straight line PA is a linear function (? 0)y？ x？ m？ m？ The image of? The straight line PB is a linear function 3 (? )y？ x？ n？ n？ m？ The image of? Point p is the intersection of two straight lines? Points A, B, C and Q are the intersections of two straight lines and the coordinate axis respectively. 1? With m? What are the coordinates of N, A, B and P and the times of ∠PAB? 2? If the area PQOB of the quadrilateral is 1 12? And CQ:AO= 1:2? Try to find the coordinates of point p? And find the functional expressions of straight lines PA and PB? 3? Are you online? 2? In the case of? Do you have a little D? With a, b, p, d as the vertex? A quadrilateral is a parallelogram? If it exists? Find the coordinates of point d? What if it doesn't exist? Please provide a justification for the answer.

There are references at the bottom. See for yourself.