PEP eighth grade mathematics volume 1 page 16-17 8-13 questions answers. Urgent

8. Prove: ∵ AC ⊥ CB, DB ⊥ CB ≌ RT △ DBC (HL) ≌ ABC = ≌ DCB ≌ ACB = ≌ DBC = 90 °

RELATED INFORMATIONS

1. The answer to the third question of congruent triangles in Chapter 11 of Volume 22 of mathematics eighth grade of new education press
2. The answers to the exercises 14.2, 6 and 7 in the first volume of mathematics published by people's education press of Grade 8 Conditions: add conditions to question 7 and find the area of the triangle formed by the line and the coordinate axis 6. Given the first-order function y = KX + B, when x = 2, the value of Y is 4, when x = - 2, the value of Y is - 2, find K and B 7. Given that the image of a function of degree passes through points (- 4,9) and (6,3), find the analytic expression of the function, and find the area of the triangle surrounded by the line and the coordinate axis
3. Eighth grade volume I mathematics book exercise 14
4. The answers to mathematics exercise 14.1 in Volume 1 of Grade 8
5. 2 answer to question 9
6. Xiaolan said, I never tell lies Xiao Ming said that what Xiao Lan said was a lie Xiao Hong said that what they said was a lie Ask, who is telling the truth, write the reason
7. The four athletes are from Beijing, Shanghai, Zhejiang and Jilin. In swimming, track and field, table tennis and football, each of them participated in only one sport, and their sports are different. In addition, they only know some fragmentary information: (1) Zhang Ming is a ball player, not a southerner; (2) Hu laochun is a southerner, not a ball player; (3) Zhang Ming is a southerner, not a ball player Li Yong shares the same room with Beijing athletes and table tennis players; (4) Zheng Yonglu is not a Beijing athlete, younger than Jilin athletes and swimmers; (5) Zhejiang athletes did not participate in the swimming competition. According to these conditions, please analyze: where are the four athletes from? What sports do you take part in?
8. During the winter vacation, Li Ming, Cao Qiang and Wang Jian each did two good things. But no one would talk about what they had done. The little reporter learned that: (1) Li Ming and their three did six good things, such as helping the military family clean up, repairing desks and chairs, taking part in the duty of the neighborhood committee, checking watches and handing them to the police, helping students make up lessons and sweeping snow on the road. (2) when Cao Qiang arrived at the military family home, he found that they had already cleaned (3) after the beginning of school, Li Ming learned that one of the students in the class insisted on helping the students make up lessons every day, and the other helped the military clean up. (4) the police went to the neighborhood committee to ask the students on duty whether they knew the students who had checked the watch. (5) the teacher praised the students who had checked the watch and handed it to the police, and he modestly said that he would learn from the students who repaired tables and chairs. (6) Cao qianghe Wang Jian learned from the neighborhood committee that the students who found the watches were their classmates. (7) the students who repaired the desks and chairs were too busy to help them make up lessons. Please answer: what's the good thing Li Ming did___ What is Cao Qiang doing___ What is Wang Jian doing___ ．
9. Read the following words and analyze the results as required. In a theft case, there are two suspect A and B, and four witnesses are being questioned. The first witness said, "I only know A theft"; second witnesses said, "I only know B is stealing"; third witnesses said, "at least one of the two testimonies is true"; fourth witnesses finally said, "I am." It is certain that the testimony of the third person is false; through investigation and research, it has been confirmed that the fourth witness told the truth, so who is the thief? Smart you, you know?
10. 5 6 6 9 ( ) 90 There is some logic between the numbers above. Please fill in the numbers in brackets
11. Grade 8 Volume 1 exercise 13 on page 75 of Mathematics Do the following formulas make sense? Why? (1) - radical 3 (2) radical - 3 (3) radical (- 3) square (4) one tenth of the square of the radical
12. Six answers to 30 pages of English homework There's no time. All right, I'll give it to you right away
13. The sixth grade mathematics class homework 10.11
14. Is the last question: 10-2 = 8km 10-4 = 6km 10:8:6 = 5:4:3 2 / 4 * 3 = 1.5km 4-1.5 = 2.5km
15. On the 1:6000000 scale map, the distance between Nanjing and Beijing is 15cm. How many kilometers is the actual distance between Nanjing and Beijing?
16. Answers on page 30 of PEP's mathematics homework fifth six .7 .8 .9 .10. A two place decimal is rounded to the nearest three point zero. The maximum is () and the minimum is () the difference between them If the original price of the dress is 200 yuan, now it's only 8 yuan. Just read a decimal point. When you write it, you forget to write the decimal point. As a result, it turns out that the decimal point may be () or () 9 The sum of the numerator and denominator of a fraction is 55. If both numerator and denominator are subtracted by five, the new fraction will be about one fourth. The original fraction is () 10. If you triple its decimal part, the number will be 2.2. If you multiply its decimal part by seven times, the number will be () 3.8
17. People's education press P33
18. Answers to page 55 of PEP's mathematics homework Design a 400 meter track for the school (1) The length of the straight runways on both sides of the 400 meter runway is 100 meters, and how long is the diameter of the two semicircles? (the width of the standard runway is 1.25 meters, and the number obtained remains integer.) (2) What is the area of the lawn on the inside of the runway (3) Long and Qingqing walk around the inside and outside of the runway. How many meters is the difference between them
19. Sequence 1, 2, 4, 12, 27. What's next? The answer is 58,
20. What is the next number in the sequence 298 209 129 58 - 4? A,-13 B,-93 C,-66 D,57