## anonymous one year ago the coordinates of the of the vertices of a triangle are A(1,3), B(9,10), and C(11,18). find the perimeter of triangle ABC. Find the perimeter of the triangle when the coordinates are multiplied by 3.

1. anonymous

2. sohailiftikhar

do you know the formula of perimeter of triangle ?

3. anonymous

you um add the three sides up?

4. sohailiftikhar

wait

5. anonymous

ok

6. anonymous

have you finally found an answer? it's 2 here :O

7. anonymous

yayyyyyyyyyyyyyy

8. sohailiftikhar

9. anonymous

at least give me the three numbers to add...

10. sohailiftikhar

ok

11. sohailiftikhar

A(1,3), B(9,10), and C(11,18). then the sides will be AB,BC,CA

12. sohailiftikhar

so now you can find the sides ig

13. anonymous

just need the three sides' number that all

14. sohailiftikhar

AB=B-A=(9-1)(10-7)=8i+3j now find it's magnitude

15. anonymous

btw when the sides all multiply by 3 the perometer just get multiplied by 3 right?

16. anonymous

does it have to be that complicated?

17. sohailiftikhar

yes

18. sohailiftikhar

first you have to find sides by distance formula then have to add then that's all .

19. anonymous

$\sqrt{(y_1+y_2)^2+(x_1+x_2)^2}$

20. anonymous

that's the formula for finding a side i THINK

21. sohailiftikhar

yes

22. anonymous

but when i plugged it in i got $$\sqrt{113}$$

23. anonymous

but how do u add them TOGETHER :O

24. anonymous

well... you are a HUMAN calculator, right?

25. anonymous

:P

26. anonymous

Use matrix method

27. anonymous

?

28. anonymous

here's what i need: i need the three numbers for the sides of the triangle, the answers for the 3 questions, and a explanation for the last question.

29. anonymous

Well let me think 2 mins plz

30. anonymous

ok

31. anonymous

the formula to find the sides are -- Distance from A to B = |dw:1441269476718:dw| In that way you can find all the sides and then for the parameter the formula is , parameter = AB+BC+AC

32. anonymous

and i know that.

33. anonymous

then what's the problem solve it

34. anonymous

XD XD

35. anonymous

idk i get a diff answer every time that's why i needa check the sides and the answer bruh!

36. anonymous

37. anonymous

well which one? i have like 20 different answers

38. anonymous

well is there root of(113)?

39. anonymous

no...

40. anonymous

side AB = root of (113)

41. anonymous

Side BC= root of (68)

42. anonymous

ok.

43. anonymous

and side CA = root of (325)

44. anonymous

then the perimeter is [ root of 113+ root of 68+root of 325]

45. anonymous

ok...

46. anonymous

are you able to do the sum?

47. sohailiftikhar

48. sohailiftikhar

which i have told before

49. anonymous

its not likie absolute tho like ther eare decimals and stuff

50. anonymous