Given that the quadrilateral ABCD is a convex quadrilateral, ab = 2, BC = 4, CD = 7, then the value range of segment ad is A: 0 < AC < 7 B: 2 < ad < 7 C: 0 < ad < 13 D: 1 < ad < 13 need to explain the reason

D：1＜AD＜13
Multiple choice questions are easy to handle
AC is between (2,6)
If AC = 5.9, then ad is between (1.1,12.9), it should be one of C and D
Take ad = 0.1, then AC can be equal to 7, which is inconsistent with "AC is between (2,6)". C is wrong
So choose D

RELATED INFORMATIONS

1. a. B is two different prime numbers. If a + B = 20 and a * b = 51, what are the values of a and B?
2. a. B is two different prime numbers. If a + B = 20, a * b = 51, then what are a and B respectively a. B is two different prime numbers. If a + B = 20, a * b = 51, then what are a and B respectively, the formula, method and idea should all be adopted,
3. The sum of two prime numbers is 20 and the product is 51. What's the difference between them
4. The prime number between 10 ` 20 has () where () digit is still a prime number after swapping position with digit on ten digit
5. Fill in the appropriate prime number in (). 10 = () + () = () + () 20 = () + () = () + ()
6. 10 = () + () = () + () fill in the appropriate prime number
7. 10 = () × (), fill in the appropriate prime number
8. Fill in the brackets with the appropriate prime number 20 = () + ()
9. What are the prime numbers within 20 What is prime
10. What are the prime numbers of 20?
11. Given that a, B, C are prime numbers and a + B + C = 86, ab = BC = AC = 971, find a, B, C I found that I had the wrong number. It should be ab + BC + AC = 971... I was wrong =. =
12. Let a, B, C be prime numbers, and a + B + C = 68, AB + BC + AC = 1121, find the value of ABC It's urgent. Please hurry up
13. If a, B and C are prime numbers, then is ab + BC + AB necessarily prime
14. Given that three different prime numbers a, B and C satisfy ABC + a = 2000, then a + B + C=______ ．
15. AB = C, if a and B are prime numbers, then C must be () emergency
16. A and B are prime numbers. The product of AB must be () A. Prime B. even C. composite D. undetermined
17. Given that three different prime numbers a, B and C satisfy ABC + a = 2000, then a + B + C=______ ．
18. If a, B, C are all prime numbers, where a is the smallest, and a + B + C = 44, AB + 3 = C, then AB + C=______ ．
19. What is the difference between the product of all prime numbers within 10 minus the smallest three digits?
20. A prime number, 10 plus it is a prime number, 20 plus it or a prime number, 70 minus it or a prime number, what is the prime number?