In the seventh grade, the second volume, the mid-term math test paper with the answer, Xuzhou No.13 Middle School 20 1 1-20 10 will do.

Select an option first (13×2 points =26 points)

1, a vertex of the Pentagon can be used as the diagonal of ().

A. 1

2, in the following equation, the binary linear equation is ()

a . xy = 1 b . x = y c . 2x+3y d . 3x+2y = 3x

3, three straight lines on the plane at least () intersect.

A.3 B.2 C. 1 D.0

4. It is known that an algebraic expression in which X is () contains y.

a . x = 10+b . y =- 15 c . x = 5+d . y =- 15

5. Given Rt△ABC, ∠ A = 30, ∠B= ().

60 or 90 days 30

6. Given that the coordinates of point A are (a2, a2+ 1), then point A is in ().

A. In the first quadrant B. In the first quadrant or on the X axis.

C. On the Y axis D. On the first quadrant or Y axis.

7, the correct proposition in the following proposition is ()

A. the internal dislocation angles are equal. B the distance from a point to a straight line is the vertical section of the point to the straight line.

C. If ∠A+∠B+∠C = 180, then ∠A, ∠B and ∠C are complementary.

D in the same plane, two straight lines perpendicular to the same straight line are parallel.

8, the following shapes with the same pattern of floor tiles can't be plane mosaic is ()

A. regular triangle B. rectangle C. regular octagon D. regular hexagon

9. Given that the coordinate of point A is (2, -3) and the AB//x axis passes through point A, the coordinate of point B is ().

A.2 B.-3 C.-1D. Not sure.

10, it is known that light is incident in the direction parallel to AB,

After being reflected by mirrors AC and AB, as shown in the figure,

If ∠ a = 40, ∠MNA= ()

100 C.60 D.80

1 1. Known: As shown in Figure B, it is located at 40 degrees southwest of A.

In the direction, c is in a.

From south to east 15 direction,

C is 80 northeast of b,

Then ∠ACB= ()

90-85 AD

12. Given that the four sides of a convex polygon are 1, 4, 6, x, then the value range of x is ().

a . 0 < x < 6b . 0 < x < 1 1c . 1 < x < 1 1d。 Can't be sure.

13. It is known that the radius of a circle centered on O is 3. if

If point C is marked as (3,45), point D should be marked as ().

A.(3，60) B.( 120，3)C.(60，3) D.(3， 120)

Two, fill in a fill (11x 3 points =33 points)

14, the sum of the outer angles of the dodecagon is _ _ _ _ _ _ _ _ _

15. If x and y are satisfied, then A (x, y) is in the _ _ _ quadrant.

16, known: straight AB, CD quilt cover

Cut with a straight line L, ∠ 1 = ∠ 2 = 85,

Then the isoseismic degree of ∠ 1 is

17, known as +(y+2)2=0,

Then the point where (x, y) is symmetrical about the origin is _ _ _ _ _

18, known as AB//CD,

∠A= 140，∠E=30，

Then ∠ c = _ _ _ _ _ _

19. it is known that point a on the y axis satisfies AO=2, then the coordinates of point a are

20. Rt△ABC, ∠ BAC = 90 is known.

AD⊥BC is D, then this number is equal.

The acute angle * * * has _ _ _ pairs.

2 1. It is known that there are balls A, B and C on the court.

A ball is 2m away from B ball, and B ball is 2m away from C ball.

Separated by 1m, then ball a and ball C.

May be _ _ _ meters apart.

Ignore the radius of the ball and fill in only one qualified number. )

22. It is known that △ABC, ∠A is 50 greater than ∠B, and ∠ C = 30, then △ABC is a _ _ _ _ _ triangle.

23. As we all know, AD⊥BC is located in D,

Then there are _ _ _ _ triangles with the height of AD in the figure * *.

Third, do a careful calculation.

25.(6 points) Known: the solution of the binary linear equations of X and Y.

Satisfy 2x- 1 = 3y, and find the value of m.

26.(6 points) It is known that the rectangular ABCD as shown in the figure is folded to the positions of D 1 and C 1 along EF.

If ∠ c 1fe = 1 15, find ∠AED 1.

27.(6 points) Eighth-grade students of Chengnan Middle School are divided into group A and group B when they go to the practice base of agricultural technical school to participate in social practice activities. The number of people in group A is three times that of group B, and there are 330 more people than group B; If five people are transferred from group B to group A, the number of people in the two groups is equal. How many students in Grade 8 will take part in this activity?

Fourth, think carefully and do it patiently.

28.(6 points) It is known that AE bisects the external angle of△ △ABC, AE//BC,

Try to judge the relationship between ∠B and ∠C, and explain the reasons.

This paper has ***6 pages.

29.(7 points) It is known that △ABC, ray BE and CF bisect ∠ABC and ∠ACB, and BE and CF intersect at point O.

(1) Verification: ∠ BOC = 90+∠ A.

(2) If the condition "CF bisects ∠ACB" is changed to "CF bisects ∠ACB adjacent outer corners", other conditions remain unchanged. Is the conclusion in (1) still valid? If it is established, explain the reasons; If not, please find out the relationship between ∠BOC and ∠A and prove it.

30.( 10) It is known that △ABC, A(2a, b-3), B (-2, 4),

C (- 1, 3), shift △ABC downward by 6 units to get △ A1b1,and then parallel it to the right by 5 units to get △A2B2C2. If the coordinate of A2 is (b-2, A- 1).

(1) Find the values of a and b.

(2) Draw △ABC in rectangular coordinate system and translate to get △A 1B 1C 1 and △A2B2C2.

(3) Find the graphic area formed by the swept part during the translation from △ABC to △A2B2C2.

(Write the results directly, without giving reasons)

Reference answer

Select an option first (13×2 points =26 points)

1 ~ 5 bb DAC 6 ~ 10 DDCBB 1 1 ~ 13 BCD

Two, fill in a fill (11x 3 points =33 points)

14.360 15.2 16.95 17.(- 1,2) 18. 1 10.

19. (0,2) or (0,2) 20.221. Any number of 1≤AC≤3 is acceptable.

22. blunt instrument 23. 6 24.(-2 100 1,0)

Third, do a careful calculation.