Looking for five geometry problems in mathematics volume 1 of grade 2 of junior high school There should be a graph and a solution. The teacher asked us to collect 5 questions. We should use the solution of grade two

In △ ABC, ad bisects ∠ BAC, De is the vertical line of BC, e is the vertical foot, through D, DM is perpendicular to AB and m, DN is perpendicular to AC and the extension line of AC is in N. prove BM = CN. Prove: ad bisects ∠ bacdm ⊥ AB, DN ⊥ AC, so DM = DN connects dB, DCDE bisects BC vertically, then DB = DCDM = dnrt △ DMB ≌ RT △ dncbm = cn6

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1. It is known that in the triangle ABC, BD and CE are the heights of the sides AC and ab respectively, and M is the midpoint of BC. If we connect de and take the midpoint o of De, what is the positional relationship between Mo and de
2. Mathematics problem in grade two of junior high school The result of simplifying M & sup2; - (m-2) - m-2 is A：m²/（m-2） B：（m²-2）/（m-2） C：4/（m-2） D：4 Please help me! Thank you! Wrong number, simplified m²/（m-2）-m-2
3. If 102x = 25, then 10-x equals () A. 15B. −15C. 150D. 1625
4. As shown in the figure, ab = AC, be ⊥ AC at point E, CF ⊥ AB at point F, be and CF intersect at point D, then ① △ Abe ≌ △ ACF; ② △ BDF ≌ △ CDE; ③ point D is on the bisector of ∠ BAC A. ①B. ②C. ①②D. ①②③
5. Just one question. Explain the reason There is a parallelogram with a length of 6 on one side. How long are his two diagonals/ A. 4 and 6 B. 4 and 8 C. 2 and 6 D. 6 and 8
6. 1. The value of the arithmetic square root-2 of estimate 27 is () A. It's between 1 and 2 B. It's between two and three C. It's between three and four D. It's between four and five 2. There are five propositions 1 / zero is the smallest real number 2 / points on the number axis cannot represent all real numbers 3. Irrational number is the number with root sign The cube root of - 1 / 27 is ± 1 / 3 5. There are two square roots of a positive number, which are opposite to each other The correct ones are: () A. 1 B.2 C.3 D.4
7. 1. It is known that the base angle of the trapezoid is 45 degrees, the height of the trapezoid is equal to the upper base, and the length of the lower ground is 9, then the waist length of the trapezoid is () A. 3 B.5 C.3 times root 2 D.2 times root 3 2. In the trapezoidal ABCD, the length of the waist BC is (), when the two base angles AB = 14cm, CD = 6cm, a = 30 ° and B = 60 ° respectively A.8cm B.6cm C.4cm D.3cm
8. For a linear function: y = KX + B, there are the following statements: (1) the larger the value of K is, the faster the straight line rises; (2) the intercept B is the distance that the straight line cuts on the Y axis; (3) when k > 0, y increases with the increase of X, K
9. Mathematics in grade two of junior high school 1. The opposite sides of two similar polygons are 3 cm and 4.5 cm respectively. If the sum of their areas is 130 square cm, then the area of the smaller polygon is 1________ square centimetre. 2. Given △ ABC ∽ a'b'c ', and ab: a'B' = 2:3, s △ ABC + s △ a'b'c '= 75, then s △ a'b'c'=______ .
10. 1. If x ^ 2 + 3x-1 = 0, then x-3 / 3x ^ 2-6x ^ (x + 2 - 5 / X-2)=________ . 2. If M / A ^ 2-B ^ 2 - 2ab-b ^ 2 / A ^ 2-B ^ 2 = A-B / A + B, then M=_______ .
11. 5 + the decimal part of root 7 is a, 11 minus the decimal part of root 7 is B, find the value of a plus B and a minus B
12. Second grade mathematics multiple choice question! Online wait for answer! Xiaohua prepared three wooden sticks to make a right triangle frame. Xiaoying accidentally cut off one of them by a third. Xiaohua can still make a right triangle as long as she takes the other two wooden sticks A. Cut off one-third B. cut off two-thirds C. both of the above can be done D. do not need to change Please explain the reason! Thank you! What's more, is the cut-off one third a proportion or a quantity??
13. 1. When x > 1 is simplification ------------------- Square of (x + 1 / x) - 4 2. The two adjacent sides of the parallelogram are 3 and 5. The length of the two line segments divided by an acute angle bisector is 3. It is known that the length of four sides of a trapezoid is 1, 2, 3 and 4 respectively, then the area of the trapezoid is
14. 9. It is known that P is a point in the parallelogram ABCD, s parallelogram ABCD = 100, then s △ PAB + s △ PCD = () It is known that the diagonals of the parallelogram ABCD intersect at point 0 If the perimeter of △ BCO is 2cm longer than that of △ AOB, then AB = ()
15. On April 18, 2004, the fifth speed increase of National Railways was made. Among them, 1084 trains from Urumqi to Chongqing had the largest speed increase. The whole journey was shortened by 9h. It is known that the journey from Urumqi to Chongqing is 3405km. The average speed before the speed increase is about 52km / h. the average speed after the speed increase is calculated. If the average speed after the speed increase is XKM / h, the equation can be formulated as follows:———————————— Reward for correct answer
16. 1. If the length of three sides of a triangle ABC is continuous even, M is the midpoint of AB, MC = ma = 5, then the area of triangle ABC is 2. On the elevator, Xiao Kai's height is 1.8 meters. If Xiao Kai's head rises 6.2 meters with the elevator, the distance of Xiao Kai's feet is 3. Given that the point P (x, y) is in the second quadrant, and Y is less than or equal to x + 4, x, y are integers, write out the coordinates of a point P that meets the above conditions 4. For the function y = (K-3) x + K, when k = it is a positive proportional function, when k = it is a linear function 5. If the solution of {ax + by = 2 is the same as that of {2x + 3Y = 4, then a =, B = ax-by=2 4x-5y=-6
17. Given vector PP1 = - (2 / 5) * vector p1p2, if vector p1p = λ PP2, then λ=
18. As shown in the figure, in the trapezoidal ABCD, ad ∥ BC, AC and BD intersect at O, and parallel lines passing through o intersect AB and CD at e and f respectively. (1) prove that OE = of; (2) if ad = 3, BC = 4, find the length of EF
19. As shown in the figure, in the diamond ABCD, ∠ a = 60 °, points P and Q are on edges AB and BC respectively, and AP = BQ Given ad = 3, AP = 2, find the length of PQ
20. The sum of two prime numbers is 99. What are the two numbers?